diff --git a/android_webview/android_webview.gyp b/android_webview/android_webview.gyp
index 2efc46c..bf9c5d1 100644
--- a/android_webview/android_webview.gyp
+++ b/android_webview/android_webview.gyp
@@ -81,6 +81,14 @@
             'pak_output': '<(PRODUCT_DIR)/android_webview_apk/assets/webviewchromium.pak',
           },
          'includes': [ '../build/repack_action.gypi' ],
+        },
+        {
+          'action_name': 'add_en_US_pak_locale',
+          'variables': {
+            'pak_inputs': ['<(SHARED_INTERMEDIATE_DIR)/webkit/webkit_strings_en-US.pak'],
+            'pak_output': '<(PRODUCT_DIR)/android_webview_apk/assets/en-US.pak',
+          },
+         'includes': [ '../build/repack_action.gypi' ],
         }
       ],
     },
diff --git a/android_webview/android_webview_pak.target.darwin-arm.mk b/android_webview/android_webview_pak.target.darwin-arm.mk
index 8c4a2d3..57a2ce6 100644
--- a/android_webview/android_webview_pak.target.darwin-arm.mk
+++ b/android_webview/android_webview_pak.target.darwin-arm.mk
@@ -29,9 +29,21 @@
 	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak" "$(gyp_shared_intermediate_dir)/content/content_resources.pak" "$(gyp_shared_intermediate_dir)/net/net_resources.pak" "$(gyp_shared_intermediate_dir)/ui/ui_resources/ui_resources_100_percent.pak" "$(gyp_shared_intermediate_dir)/webkit/blink_resources.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_resources_100_percent.pak"
 
 
+### Rules for action "add_en_US_pak_locale":
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_local_path := $(LOCAL_PATH)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_var_prefix := $(GYP_VAR_PREFIX)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_intermediate_dir := $(abspath $(gyp_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_shared_intermediate_dir := $(abspath $(gyp_shared_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: export PATH := $(subst $(ANDROID_BUILD_PATHS),,$(PATH))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: $(LOCAL_PATH)/tools/grit/grit/format/repack.py $(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak $(GYP_TARGET_DEPENDENCIES)
+	@echo "Gyp action: android_webview_android_webview_gyp_android_webview_pak_target_add_en_US_pak_locale ($@)"
+	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak"
+
+
 
 GYP_GENERATED_OUTPUTS := \
-	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak \
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak
 
 # Make sure our deps and generated files are built first.
 LOCAL_ADDITIONAL_DEPENDENCIES := $(GYP_TARGET_DEPENDENCIES) $(GYP_GENERATED_OUTPUTS)
diff --git a/android_webview/android_webview_pak.target.darwin-arm64.mk b/android_webview/android_webview_pak.target.darwin-arm64.mk
index 8c4a2d3..57a2ce6 100644
--- a/android_webview/android_webview_pak.target.darwin-arm64.mk
+++ b/android_webview/android_webview_pak.target.darwin-arm64.mk
@@ -29,9 +29,21 @@
 	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak" "$(gyp_shared_intermediate_dir)/content/content_resources.pak" "$(gyp_shared_intermediate_dir)/net/net_resources.pak" "$(gyp_shared_intermediate_dir)/ui/ui_resources/ui_resources_100_percent.pak" "$(gyp_shared_intermediate_dir)/webkit/blink_resources.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_resources_100_percent.pak"
 
 
+### Rules for action "add_en_US_pak_locale":
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_local_path := $(LOCAL_PATH)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_var_prefix := $(GYP_VAR_PREFIX)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_intermediate_dir := $(abspath $(gyp_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_shared_intermediate_dir := $(abspath $(gyp_shared_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: export PATH := $(subst $(ANDROID_BUILD_PATHS),,$(PATH))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: $(LOCAL_PATH)/tools/grit/grit/format/repack.py $(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak $(GYP_TARGET_DEPENDENCIES)
+	@echo "Gyp action: android_webview_android_webview_gyp_android_webview_pak_target_add_en_US_pak_locale ($@)"
+	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak"
+
+
 
 GYP_GENERATED_OUTPUTS := \
-	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak \
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak
 
 # Make sure our deps and generated files are built first.
 LOCAL_ADDITIONAL_DEPENDENCIES := $(GYP_TARGET_DEPENDENCIES) $(GYP_GENERATED_OUTPUTS)
diff --git a/android_webview/android_webview_pak.target.darwin-mips.mk b/android_webview/android_webview_pak.target.darwin-mips.mk
index 8c4a2d3..57a2ce6 100644
--- a/android_webview/android_webview_pak.target.darwin-mips.mk
+++ b/android_webview/android_webview_pak.target.darwin-mips.mk
@@ -29,9 +29,21 @@
 	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak" "$(gyp_shared_intermediate_dir)/content/content_resources.pak" "$(gyp_shared_intermediate_dir)/net/net_resources.pak" "$(gyp_shared_intermediate_dir)/ui/ui_resources/ui_resources_100_percent.pak" "$(gyp_shared_intermediate_dir)/webkit/blink_resources.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_resources_100_percent.pak"
 
 
+### Rules for action "add_en_US_pak_locale":
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_local_path := $(LOCAL_PATH)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_var_prefix := $(GYP_VAR_PREFIX)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_intermediate_dir := $(abspath $(gyp_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_shared_intermediate_dir := $(abspath $(gyp_shared_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: export PATH := $(subst $(ANDROID_BUILD_PATHS),,$(PATH))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: $(LOCAL_PATH)/tools/grit/grit/format/repack.py $(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak $(GYP_TARGET_DEPENDENCIES)
+	@echo "Gyp action: android_webview_android_webview_gyp_android_webview_pak_target_add_en_US_pak_locale ($@)"
+	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak"
+
+
 
 GYP_GENERATED_OUTPUTS := \
-	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak \
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak
 
 # Make sure our deps and generated files are built first.
 LOCAL_ADDITIONAL_DEPENDENCIES := $(GYP_TARGET_DEPENDENCIES) $(GYP_GENERATED_OUTPUTS)
diff --git a/android_webview/android_webview_pak.target.darwin-x86.mk b/android_webview/android_webview_pak.target.darwin-x86.mk
index 8c4a2d3..57a2ce6 100644
--- a/android_webview/android_webview_pak.target.darwin-x86.mk
+++ b/android_webview/android_webview_pak.target.darwin-x86.mk
@@ -29,9 +29,21 @@
 	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak" "$(gyp_shared_intermediate_dir)/content/content_resources.pak" "$(gyp_shared_intermediate_dir)/net/net_resources.pak" "$(gyp_shared_intermediate_dir)/ui/ui_resources/ui_resources_100_percent.pak" "$(gyp_shared_intermediate_dir)/webkit/blink_resources.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_resources_100_percent.pak"
 
 
+### Rules for action "add_en_US_pak_locale":
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_local_path := $(LOCAL_PATH)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_var_prefix := $(GYP_VAR_PREFIX)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_intermediate_dir := $(abspath $(gyp_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_shared_intermediate_dir := $(abspath $(gyp_shared_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: export PATH := $(subst $(ANDROID_BUILD_PATHS),,$(PATH))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: $(LOCAL_PATH)/tools/grit/grit/format/repack.py $(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak $(GYP_TARGET_DEPENDENCIES)
+	@echo "Gyp action: android_webview_android_webview_gyp_android_webview_pak_target_add_en_US_pak_locale ($@)"
+	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak"
+
+
 
 GYP_GENERATED_OUTPUTS := \
-	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak \
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak
 
 # Make sure our deps and generated files are built first.
 LOCAL_ADDITIONAL_DEPENDENCIES := $(GYP_TARGET_DEPENDENCIES) $(GYP_GENERATED_OUTPUTS)
diff --git a/android_webview/android_webview_pak.target.darwin-x86_64.mk b/android_webview/android_webview_pak.target.darwin-x86_64.mk
index 8c4a2d3..57a2ce6 100644
--- a/android_webview/android_webview_pak.target.darwin-x86_64.mk
+++ b/android_webview/android_webview_pak.target.darwin-x86_64.mk
@@ -29,9 +29,21 @@
 	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak" "$(gyp_shared_intermediate_dir)/content/content_resources.pak" "$(gyp_shared_intermediate_dir)/net/net_resources.pak" "$(gyp_shared_intermediate_dir)/ui/ui_resources/ui_resources_100_percent.pak" "$(gyp_shared_intermediate_dir)/webkit/blink_resources.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_resources_100_percent.pak"
 
 
+### Rules for action "add_en_US_pak_locale":
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_local_path := $(LOCAL_PATH)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_var_prefix := $(GYP_VAR_PREFIX)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_intermediate_dir := $(abspath $(gyp_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_shared_intermediate_dir := $(abspath $(gyp_shared_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: export PATH := $(subst $(ANDROID_BUILD_PATHS),,$(PATH))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: $(LOCAL_PATH)/tools/grit/grit/format/repack.py $(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak $(GYP_TARGET_DEPENDENCIES)
+	@echo "Gyp action: android_webview_android_webview_gyp_android_webview_pak_target_add_en_US_pak_locale ($@)"
+	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak"
+
+
 
 GYP_GENERATED_OUTPUTS := \
-	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak \
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak
 
 # Make sure our deps and generated files are built first.
 LOCAL_ADDITIONAL_DEPENDENCIES := $(GYP_TARGET_DEPENDENCIES) $(GYP_GENERATED_OUTPUTS)
diff --git a/android_webview/android_webview_pak.target.linux-arm.mk b/android_webview/android_webview_pak.target.linux-arm.mk
index 8c4a2d3..57a2ce6 100644
--- a/android_webview/android_webview_pak.target.linux-arm.mk
+++ b/android_webview/android_webview_pak.target.linux-arm.mk
@@ -29,9 +29,21 @@
 	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak" "$(gyp_shared_intermediate_dir)/content/content_resources.pak" "$(gyp_shared_intermediate_dir)/net/net_resources.pak" "$(gyp_shared_intermediate_dir)/ui/ui_resources/ui_resources_100_percent.pak" "$(gyp_shared_intermediate_dir)/webkit/blink_resources.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_resources_100_percent.pak"
 
 
+### Rules for action "add_en_US_pak_locale":
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_local_path := $(LOCAL_PATH)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_var_prefix := $(GYP_VAR_PREFIX)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_intermediate_dir := $(abspath $(gyp_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_shared_intermediate_dir := $(abspath $(gyp_shared_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: export PATH := $(subst $(ANDROID_BUILD_PATHS),,$(PATH))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: $(LOCAL_PATH)/tools/grit/grit/format/repack.py $(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak $(GYP_TARGET_DEPENDENCIES)
+	@echo "Gyp action: android_webview_android_webview_gyp_android_webview_pak_target_add_en_US_pak_locale ($@)"
+	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak"
+
+
 
 GYP_GENERATED_OUTPUTS := \
-	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak \
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak
 
 # Make sure our deps and generated files are built first.
 LOCAL_ADDITIONAL_DEPENDENCIES := $(GYP_TARGET_DEPENDENCIES) $(GYP_GENERATED_OUTPUTS)
diff --git a/android_webview/android_webview_pak.target.linux-arm64.mk b/android_webview/android_webview_pak.target.linux-arm64.mk
index 8c4a2d3..57a2ce6 100644
--- a/android_webview/android_webview_pak.target.linux-arm64.mk
+++ b/android_webview/android_webview_pak.target.linux-arm64.mk
@@ -29,9 +29,21 @@
 	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak" "$(gyp_shared_intermediate_dir)/content/content_resources.pak" "$(gyp_shared_intermediate_dir)/net/net_resources.pak" "$(gyp_shared_intermediate_dir)/ui/ui_resources/ui_resources_100_percent.pak" "$(gyp_shared_intermediate_dir)/webkit/blink_resources.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_resources_100_percent.pak"
 
 
+### Rules for action "add_en_US_pak_locale":
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_local_path := $(LOCAL_PATH)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_var_prefix := $(GYP_VAR_PREFIX)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_intermediate_dir := $(abspath $(gyp_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_shared_intermediate_dir := $(abspath $(gyp_shared_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: export PATH := $(subst $(ANDROID_BUILD_PATHS),,$(PATH))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: $(LOCAL_PATH)/tools/grit/grit/format/repack.py $(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak $(GYP_TARGET_DEPENDENCIES)
+	@echo "Gyp action: android_webview_android_webview_gyp_android_webview_pak_target_add_en_US_pak_locale ($@)"
+	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak"
+
+
 
 GYP_GENERATED_OUTPUTS := \
-	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak \
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak
 
 # Make sure our deps and generated files are built first.
 LOCAL_ADDITIONAL_DEPENDENCIES := $(GYP_TARGET_DEPENDENCIES) $(GYP_GENERATED_OUTPUTS)
diff --git a/android_webview/android_webview_pak.target.linux-mips.mk b/android_webview/android_webview_pak.target.linux-mips.mk
index 8c4a2d3..57a2ce6 100644
--- a/android_webview/android_webview_pak.target.linux-mips.mk
+++ b/android_webview/android_webview_pak.target.linux-mips.mk
@@ -29,9 +29,21 @@
 	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak" "$(gyp_shared_intermediate_dir)/content/content_resources.pak" "$(gyp_shared_intermediate_dir)/net/net_resources.pak" "$(gyp_shared_intermediate_dir)/ui/ui_resources/ui_resources_100_percent.pak" "$(gyp_shared_intermediate_dir)/webkit/blink_resources.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_resources_100_percent.pak"
 
 
+### Rules for action "add_en_US_pak_locale":
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_local_path := $(LOCAL_PATH)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_var_prefix := $(GYP_VAR_PREFIX)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_intermediate_dir := $(abspath $(gyp_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_shared_intermediate_dir := $(abspath $(gyp_shared_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: export PATH := $(subst $(ANDROID_BUILD_PATHS),,$(PATH))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: $(LOCAL_PATH)/tools/grit/grit/format/repack.py $(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak $(GYP_TARGET_DEPENDENCIES)
+	@echo "Gyp action: android_webview_android_webview_gyp_android_webview_pak_target_add_en_US_pak_locale ($@)"
+	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak"
+
+
 
 GYP_GENERATED_OUTPUTS := \
-	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak \
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak
 
 # Make sure our deps and generated files are built first.
 LOCAL_ADDITIONAL_DEPENDENCIES := $(GYP_TARGET_DEPENDENCIES) $(GYP_GENERATED_OUTPUTS)
diff --git a/android_webview/android_webview_pak.target.linux-x86.mk b/android_webview/android_webview_pak.target.linux-x86.mk
index 8c4a2d3..57a2ce6 100644
--- a/android_webview/android_webview_pak.target.linux-x86.mk
+++ b/android_webview/android_webview_pak.target.linux-x86.mk
@@ -29,9 +29,21 @@
 	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak" "$(gyp_shared_intermediate_dir)/content/content_resources.pak" "$(gyp_shared_intermediate_dir)/net/net_resources.pak" "$(gyp_shared_intermediate_dir)/ui/ui_resources/ui_resources_100_percent.pak" "$(gyp_shared_intermediate_dir)/webkit/blink_resources.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_resources_100_percent.pak"
 
 
+### Rules for action "add_en_US_pak_locale":
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_local_path := $(LOCAL_PATH)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_var_prefix := $(GYP_VAR_PREFIX)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_intermediate_dir := $(abspath $(gyp_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_shared_intermediate_dir := $(abspath $(gyp_shared_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: export PATH := $(subst $(ANDROID_BUILD_PATHS),,$(PATH))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: $(LOCAL_PATH)/tools/grit/grit/format/repack.py $(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak $(GYP_TARGET_DEPENDENCIES)
+	@echo "Gyp action: android_webview_android_webview_gyp_android_webview_pak_target_add_en_US_pak_locale ($@)"
+	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak"
+
+
 
 GYP_GENERATED_OUTPUTS := \
-	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak \
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak
 
 # Make sure our deps and generated files are built first.
 LOCAL_ADDITIONAL_DEPENDENCIES := $(GYP_TARGET_DEPENDENCIES) $(GYP_GENERATED_OUTPUTS)
diff --git a/android_webview/android_webview_pak.target.linux-x86_64.mk b/android_webview/android_webview_pak.target.linux-x86_64.mk
index 8c4a2d3..57a2ce6 100644
--- a/android_webview/android_webview_pak.target.linux-x86_64.mk
+++ b/android_webview/android_webview_pak.target.linux-x86_64.mk
@@ -29,9 +29,21 @@
 	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak" "$(gyp_shared_intermediate_dir)/content/content_resources.pak" "$(gyp_shared_intermediate_dir)/net/net_resources.pak" "$(gyp_shared_intermediate_dir)/ui/ui_resources/ui_resources_100_percent.pak" "$(gyp_shared_intermediate_dir)/webkit/blink_resources.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_resources_100_percent.pak"
 
 
+### Rules for action "add_en_US_pak_locale":
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_local_path := $(LOCAL_PATH)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_var_prefix := $(GYP_VAR_PREFIX)
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_intermediate_dir := $(abspath $(gyp_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: gyp_shared_intermediate_dir := $(abspath $(gyp_shared_intermediate_dir))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: export PATH := $(subst $(ANDROID_BUILD_PATHS),,$(PATH))
+$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak: $(LOCAL_PATH)/tools/grit/grit/format/repack.py $(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak $(GYP_TARGET_DEPENDENCIES)
+	@echo "Gyp action: android_webview_android_webview_gyp_android_webview_pak_target_add_en_US_pak_locale ($@)"
+	$(hide)cd $(gyp_local_path)/android_webview; mkdir -p $(gyp_shared_intermediate_dir)/android_webview_apk/assets; python ../tools/grit/grit/format/repack.py "$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak" "$(gyp_shared_intermediate_dir)/webkit/webkit_strings_en-US.pak"
+
+
 
 GYP_GENERATED_OUTPUTS := \
-	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/webviewchromium.pak \
+	$(gyp_shared_intermediate_dir)/android_webview_apk/assets/en-US.pak
 
 # Make sure our deps and generated files are built first.
 LOCAL_ADDITIONAL_DEPENDENCIES := $(GYP_TARGET_DEPENDENCIES) $(GYP_GENERATED_OUTPUTS)
diff --git a/android_webview/android_webview_tests.gypi b/android_webview/android_webview_tests.gypi
index 390732a..95731df 100644
--- a/android_webview/android_webview_tests.gypi
+++ b/android_webview/android_webview_tests.gypi
@@ -16,8 +16,10 @@
         'java_in_dir': 'test/shell',
         'native_lib_target': 'libstandalonelibwebviewchromium',
         'resource_dir': 'test/shell/res',
+        'extensions_to_not_compress': 'pak',
         'additional_input_paths': [
           '<(PRODUCT_DIR)/android_webview_apk/assets/webviewchromium.pak',
+          '<(PRODUCT_DIR)/android_webview_apk/assets/en-US.pak',
           '<(PRODUCT_DIR)/android_webview_apk/assets/asset_file.html',
           '<(PRODUCT_DIR)/android_webview_apk/assets/cookie_test.html',
           '<(PRODUCT_DIR)/android_webview_apk/assets/asset_icon.png',
diff --git a/android_webview/browser/DEPS b/android_webview/browser/DEPS
index 417b2c9..eb70713 100644
--- a/android_webview/browser/DEPS
+++ b/android_webview/browser/DEPS
@@ -2,6 +2,7 @@
   "-android_webview",
   "+android_webview/browser",
   "+android_webview/common",
+  "+android_webview/native",
   "+android_webview/public/browser",
 
   "+cc",
diff --git a/android_webview/browser/aw_browser_main_parts.cc b/android_webview/browser/aw_browser_main_parts.cc
index 29e9003..2abc6c2 100644
--- a/android_webview/browser/aw_browser_main_parts.cc
+++ b/android_webview/browser/aw_browser_main_parts.cc
@@ -6,6 +6,7 @@
 
 #include "android_webview/browser/aw_browser_context.h"
 #include "android_webview/browser/aw_result_codes.h"
+#include "android_webview/native/aw_assets.h"
 #include "base/android/build_info.h"
 #include "base/android/memory_pressure_listener_android.h"
 #include "base/command_line.h"
@@ -19,6 +20,7 @@
 #include "gpu/command_buffer/service/mailbox_synchronizer.h"
 #include "net/android/network_change_notifier_factory_android.h"
 #include "net/base/network_change_notifier.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/base/l10n/l10n_util_android.h"
 #include "ui/base/layout.h"
 #include "ui/base/resource/resource_bundle.h"
@@ -45,15 +47,57 @@
 }
 
 int AwBrowserMainParts::PreCreateThreads() {
-  ui::ResourceBundle::InitSharedInstanceLocaleOnly(
-      l10n_util::GetDefaultLocale(), NULL);
+  int pak_fd = 0;
+  int64 pak_off = 0;
+  int64 pak_len = 0;
 
-  base::FilePath pak_path;
-  PathService::Get(ui::DIR_RESOURCE_PAKS_ANDROID, &pak_path);
+  // TODO(primiano): at present state there is a cyclic logic dependency
+  // between l10n_util::GetApplicationLocale and our code here. l10n_util
+  // decides which locale to ultimately use by scanning the pak files in the
+  // data folder. What we ultimately want to achieve is knowing the pak file to
+  // load from the apk beforehand, without looking at the data folder at all.
+  // Fixing this cyclic dependency involves some refactoring in ResourceBundle
+  // and l10n_util.
+  // In the meanwhile we use the mmap path only as a fallback (i.e. we check
+  // first for the existence of the pak files in the data dir). In the immediate
+  // future this order should be reversed, and we should look in the data
+  // directory only if we failed to mmap the pak file from the apk.
+  bool did_init_from_file = !ui::ResourceBundle::InitSharedInstanceLocaleOnly(
+                                 l10n_util::GetDefaultLocale(), NULL).empty();
+  if (!did_init_from_file) {
+    LOG(WARNING) << "Failed to load the locale pak from PATH_SERVICE. "
+                    " Trying to mmap en-US.pak from the apk";
+    if (AwAssets::OpenAsset("en-US.pak", &pak_fd, &pak_off, &pak_len)) {
+      VLOG(0) << "Load from apk succesful, fd=" << pak_fd << " off=" << pak_off
+              << " len=" << pak_len;
+      ui::ResourceBundle::CleanupSharedInstance();
+      ui::ResourceBundle::InitSharedInstanceWithPakFileRegion(
+          base::File(pak_fd),
+          base::MemoryMappedFile::Region(pak_off, pak_len),
+          /*should_load_common_resources=*/false);
+    } else {
+      LOG(WARNING) << "Failed to load en-US.pak from the apk too. "
+                      "Bringing up WebView without any locale";
+    }
+  }
 
-  ui::ResourceBundle::GetSharedInstance().AddDataPackFromPath(
-      pak_path.AppendASCII("webviewchromium.pak"),
-      ui::SCALE_FACTOR_NONE);
+  // Try to directly mmap the webviewchromium.pak from the apk. Fall back to
+  // load from file, using PATH_SERVICE, otherwise.
+  if (AwAssets::OpenAsset("webviewchromium.pak", &pak_fd, &pak_off, &pak_len)) {
+    VLOG(0) << "Loading webviewchromium.pak from, fd:" << pak_fd
+            << " off:" << pak_off << " len:" << pak_len;
+    ui::ResourceBundle::GetSharedInstance().AddDataPackFromFileRegion(
+        base::File(pak_fd),
+        base::MemoryMappedFile::Region(pak_off, pak_len),
+        ui::SCALE_FACTOR_NONE);
+  } else {
+    base::FilePath pak_path;
+    PathService::Get(ui::DIR_RESOURCE_PAKS_ANDROID, &pak_path);
+    LOG(WARNING) << "Cannot load webviewchromium.pak assets from the apk. "
+                    "Falling back loading it from " << pak_path.MaybeAsASCII();
+    ui::ResourceBundle::GetSharedInstance().AddDataPackFromPath(
+        pak_path.AppendASCII("webviewchromium.pak"), ui::SCALE_FACTOR_NONE);
+  }
 
   base::android::MemoryPressureListenerAndroid::RegisterSystemCallback(
       base::android::AttachCurrentThread());
diff --git a/android_webview/test/shell/src/org/chromium/android_webview/shell/AwShellApplication.java b/android_webview/test/shell/src/org/chromium/android_webview/shell/AwShellApplication.java
index b019d8a..697bbff 100644
--- a/android_webview/test/shell/src/org/chromium/android_webview/shell/AwShellApplication.java
+++ b/android_webview/test/shell/src/org/chromium/android_webview/shell/AwShellApplication.java
@@ -21,9 +21,7 @@
 
     private static final String TAG = "AwShellApplication";
     /** The minimum set of .pak files the test runner needs. */
-    private static final String[] MANDATORY_PAKS = {
-        "webviewchromium.pak", "en-US.pak", "icudtl.dat"
-    };
+    private static final String[] MANDATORY_PAKS = { "icudtl.dat" };
 
     @Override
     public void onCreate() {
diff --git a/build/android/gyp/package_resources.py b/build/android/gyp/package_resources.py
index 7a7e16c..77cc276 100755
--- a/build/android/gyp/package_resources.py
+++ b/build/android/gyp/package_resources.py
@@ -40,6 +40,8 @@
                     help='zip files containing resources to be packaged')
   parser.add_option('--asset-dir',
                     help='directories containing assets to be packaged')
+  parser.add_option('--no-compress', help='disables compression for the '
+                    'given comma separated list of extensions')
 
   parser.add_option('--apk-path',
                     help='Path to output (partial) apk.')
@@ -104,6 +106,10 @@
                        '-F', options.apk_path,
                        ]
 
+    if options.no_compress:
+      for ext in options.no_compress.split(','):
+        package_command += ['-0', ext]
+
     if os.path.exists(options.asset_dir):
       package_command += ['-A', options.asset_dir]
 
diff --git a/build/java_apk.gypi b/build/java_apk.gypi
index bef0811..0296210 100644
--- a/build/java_apk.gypi
+++ b/build/java_apk.gypi
@@ -72,6 +72,7 @@
     'dependencies_res_zip_paths': [],
     'additional_res_packages': [],
     'is_test_apk%': 0,
+    'extensions_to_not_compress%': '',
     'resource_input_paths': [],
     'intermediate_dir': '<(PRODUCT_DIR)/<(_target_name)',
     'asset_location%': '<(intermediate_dir)/assets',
@@ -772,6 +773,8 @@
         '--asset-dir', '<(asset_location)',
         '--resource-zips', '>(package_resource_zip_input_paths)',
 
+        '--no-compress', '<(extensions_to_not_compress)',
+
         '--apk-path', '<(resource_packaged_apk_path)',
       ],
     },
diff --git a/chrome/app/chrome_main_delegate.cc b/chrome/app/chrome_main_delegate.cc
index 6dbb03a..e0816e1 100644
--- a/chrome/app/chrome_main_delegate.cc
+++ b/chrome/app/chrome_main_delegate.cc
@@ -706,8 +706,10 @@
     int locale_pak_fd = base::GlobalDescriptors::GetInstance()->MaybeGet(
         kAndroidLocalePakDescriptor);
     CHECK(locale_pak_fd != -1);
-    ResourceBundle::InitSharedInstanceWithPakFile(base::File(locale_pak_fd),
-                                                  false);
+    ResourceBundle::InitSharedInstanceWithPakFileRegion(
+        base::File(locale_pak_fd),
+        base::MemoryMappedFile::Region::kWholeFile,
+        false);
 
     int extra_pak_keys[] = {
       kAndroidChrome100PercentPakDescriptor,
diff --git a/content/shell/app/shell_main_delegate.cc b/content/shell/app/shell_main_delegate.cc
index 773e0ae..bd5c7cf 100644
--- a/content/shell/app/shell_main_delegate.cc
+++ b/content/shell/app/shell_main_delegate.cc
@@ -264,8 +264,8 @@
       base::GlobalDescriptors::GetInstance()->MaybeGet(kShellPakDescriptor);
   if (pak_fd >= 0) {
     // This is clearly wrong. See crbug.com/330930
-    ui::ResourceBundle::InitSharedInstanceWithPakFile(base::File(pak_fd),
-                                                      false);
+    ui::ResourceBundle::InitSharedInstanceWithPakFileRegion(
+        base::File(pak_fd), base::MemoryMappedFile::Region::kWholeFile, false);
     ResourceBundle::GetSharedInstance().AddDataPackFromFile(
         base::File(pak_fd), ui::SCALE_FACTOR_100P);
     return;
diff --git a/ui/base/resource/resource_bundle.cc b/ui/base/resource/resource_bundle.cc
index c070585..cd1c077 100644
--- a/ui/base/resource/resource_bundle.cc
+++ b/ui/base/resource/resource_bundle.cc
@@ -174,15 +174,17 @@
 }
 
 // static
-void ResourceBundle::InitSharedInstanceWithPakFile(
-    base::File pak_file, bool should_load_common_resources) {
+void ResourceBundle::InitSharedInstanceWithPakFileRegion(
+    base::File pak_file,
+    const base::MemoryMappedFile::Region& region,
+    bool should_load_common_resources) {
   InitSharedInstance(NULL);
   if (should_load_common_resources)
     g_shared_instance_->LoadCommonResources();
 
   scoped_ptr<DataPack> data_pack(
       new DataPack(SCALE_FACTOR_100P));
-  if (!data_pack->LoadFromFile(pak_file.Pass())) {
+  if (!data_pack->LoadFromFileRegion(pak_file.Pass(), region)) {
     NOTREACHED() << "failed to load pak file";
     return;
   }
diff --git a/ui/base/resource/resource_bundle.h b/ui/base/resource/resource_bundle.h
index c17ff30..8adfee7 100644
--- a/ui/base/resource/resource_bundle.h
+++ b/ui/base/resource/resource_bundle.h
@@ -131,12 +131,16 @@
   static std::string InitSharedInstanceLocaleOnly(
       const std::string& pref_locale, Delegate* delegate);
 
-  // Initialize the ResourceBundle using given file. The second argument
-  // controls whether or not ResourceBundle::LoadCommonResources is called.
+  // Initialize the ResourceBundle using the given file region. If |region| is
+  // MemoryMappedFile::Region::kWholeFile, the entire |pak_file| is used.
+  // |should_load_common_resources| controls whether or not LoadCommonResources
+  // is called.
   // This allows the use of this function in a sandbox without local file
   // access (as on Android).
-  static void InitSharedInstanceWithPakFile(base::File file,
-                                            bool should_load_common_resources);
+  static void InitSharedInstanceWithPakFileRegion(
+      base::File pak_file,
+      const base::MemoryMappedFile::Region& region,
+      bool should_load_common_resources);
 
   // Initialize the ResourceBundle using given data pack path for testing.
   static void InitSharedInstanceWithPakPath(const base::FilePath& path);