diff --git a/BUILD.gn b/BUILD.gn
index a6cc4b5..d3c7500 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -6,12 +6,13 @@
 import("//build/config/android/rules.gni")
 
 android_library("boundary_interface_java") {
-  java_files = [
+  sources = [
     "src/org/chromium/support_lib_boundary/FeatureFlagHolderBoundaryInterface.java",
     "src/org/chromium/support_lib_boundary/IsomorphicObjectBoundaryInterface.java",
     "src/org/chromium/support_lib_boundary/JsReplyProxyBoundaryInterface.java",
     "src/org/chromium/support_lib_boundary/ProxyControllerBoundaryInterface.java",
     "src/org/chromium/support_lib_boundary/SafeBrowsingResponseBoundaryInterface.java",
+    "src/org/chromium/support_lib_boundary/ScriptReferenceBoundaryInterface.java",
     "src/org/chromium/support_lib_boundary/ServiceWorkerClientBoundaryInterface.java",
     "src/org/chromium/support_lib_boundary/ServiceWorkerControllerBoundaryInterface.java",
     "src/org/chromium/support_lib_boundary/ServiceWorkerWebSettingsBoundaryInterface.java",
@@ -41,13 +42,23 @@
   # build when we mirror this into AndroidX. We are only permitted to depend on
   # core Android classes and other AndroidX classes (must be in the androidx.*
   # package name).
-  deps = [
-    "//third_party/android_deps:androidx_annotation_annotation_java",
-  ]
+  deps = [ "//third_party/android_deps:androidx_annotation_annotation_java" ]
+}
 
-  # This is to verify the boundary interfaces compile and lint correctly against
-  # the minSdkVersion of the webkit support library module. As the minSdkVersion
-  # of the support library increases, so should this value. See
+android_apk("boundary_interface_example_apk") {
+  apk_name = "BoundaryInterfaceExample"
+
+  # Use a dummy android manifest since this code is copied to androidx.
+  android_manifest = "//build/android/AndroidManifest.xml"
+
+  # This is to verify that the boundary interfaces compile and lint correctly
+  # against the minSdkVersion of the webkit support library module. As the
+  # minSdkVersion of the support library increases, so should this value. See
   # http://crbug.com/828184 for more details.
   min_sdk_version = 14
+
+  # Explicitly enable lint for this apk.
+  enable_lint = true
+
+  deps = [ ":boundary_interface_java" ]
 }
diff --git a/build.gradle b/build.gradle
deleted file mode 100644
index 4fbc108..0000000
--- a/build.gradle
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright 2019 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// This file is to build WebView boundary interfaces as part of the AndroidX webkit library.
-// It is not meant to be used or build any targets in chromium project.
-
-import androidx.build.SdkHelperKt
-import androidx.build.SupportConfig
-
-plugins {
-    id('java-library')
-}
-
-dependencies {
-    api("androidx.annotation:annotation:1.1.0")
-    implementation fileTree(dir: "${SdkHelperKt.getSdkPath(project.rootDir)}/platforms/$SupportConfig.COMPILE_SDK_VERSION/",
-            include: "android.jar")
-}
-
-sourceSets {
-    main {
-        java.srcDirs = ['src']
-    }
-}
diff --git a/src/org/chromium/support_lib_boundary/ScriptReferenceBoundaryInterface.java b/src/org/chromium/support_lib_boundary/ScriptReferenceBoundaryInterface.java
new file mode 100644
index 0000000..6358e00
--- /dev/null
+++ b/src/org/chromium/support_lib_boundary/ScriptReferenceBoundaryInterface.java
@@ -0,0 +1,12 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.support_lib_boundary;
+
+/**
+ * Boundary interface for AwContents.addDocumentStartJavascript().
+ */
+public interface ScriptReferenceBoundaryInterface {
+    void remove();
+}
diff --git a/src/org/chromium/support_lib_boundary/StaticsBoundaryInterface.java b/src/org/chromium/support_lib_boundary/StaticsBoundaryInterface.java
index 648d416..c2d3864 100644
--- a/src/org/chromium/support_lib_boundary/StaticsBoundaryInterface.java
+++ b/src/org/chromium/support_lib_boundary/StaticsBoundaryInterface.java
@@ -9,12 +9,14 @@
 import android.webkit.ValueCallback;
 
 import java.util.List;
+import java.util.Set;
 
 /**
  * Boundary interface for WebViewFactoryProvider.Statics.
  */
 public interface StaticsBoundaryInterface {
     void initSafeBrowsing(Context context, ValueCallback<Boolean> callback);
+    void setSafeBrowsingAllowlist(Set<String> hosts, ValueCallback<Boolean> callback);
     void setSafeBrowsingWhitelist(List<String> hosts, ValueCallback<Boolean> callback);
     Uri getSafeBrowsingPrivacyPolicyUrl();
     boolean isMultiProcessEnabled();
diff --git a/src/org/chromium/support_lib_boundary/WebViewProviderBoundaryInterface.java b/src/org/chromium/support_lib_boundary/WebViewProviderBoundaryInterface.java
index bb677ef..843d387 100644
--- a/src/org/chromium/support_lib_boundary/WebViewProviderBoundaryInterface.java
+++ b/src/org/chromium/support_lib_boundary/WebViewProviderBoundaryInterface.java
@@ -20,6 +20,8 @@
     void addWebMessageListener(String jsObjectName, String[] allowedOriginRules,
             /* WebMessageListener */ InvocationHandler listener);
     void removeWebMessageListener(String jsObjectName);
+    /* ScriptReference */ InvocationHandler addDocumentStartJavaScript(
+            String script, String[] allowedOriginRules);
     WebViewClient getWebViewClient();
     WebChromeClient getWebChromeClient();
     /* WebViewRenderer */ InvocationHandler getWebViewRenderer();
diff --git a/src/org/chromium/support_lib_boundary/WebViewProviderFactoryBoundaryInterface.java b/src/org/chromium/support_lib_boundary/WebViewProviderFactoryBoundaryInterface.java
index 15db689..902a04b 100644
--- a/src/org/chromium/support_lib_boundary/WebViewProviderFactoryBoundaryInterface.java
+++ b/src/org/chromium/support_lib_boundary/WebViewProviderFactoryBoundaryInterface.java
@@ -18,4 +18,5 @@
     /* SupportLibraryServiceWorkerController */ InvocationHandler getServiceWorkerController();
     /* SupportLibraryTracingController */ InvocationHandler getTracingController();
     /* SupportLibraryProxyController */ InvocationHandler getProxyController();
+    void setSupportLibraryVersion(String version);
 }
diff --git a/src/org/chromium/support_lib_boundary/util/BoundaryInterfaceReflectionUtil.java b/src/org/chromium/support_lib_boundary/util/BoundaryInterfaceReflectionUtil.java
index 1c5f369..c2dc613 100644
--- a/src/org/chromium/support_lib_boundary/util/BoundaryInterfaceReflectionUtil.java
+++ b/src/org/chromium/support_lib_boundary/util/BoundaryInterfaceReflectionUtil.java
@@ -3,12 +3,11 @@
 // found in the LICENSE file.
 package org.chromium.support_lib_boundary.util;
 
-import android.annotation.SuppressLint;
-import android.annotation.TargetApi;
 import android.os.Build;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
 
 import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.InvocationTargetException;
@@ -22,7 +21,6 @@
  */
 // Although this is not enforced in chromium, this is a requirement enforced when this file is
 // mirrored into AndroidX. See http://b/120770118 for details.
-@SuppressLint("BanTargetApiAnnotation")
 public class BoundaryInterfaceReflectionUtil {
     /**
      * Check if an object is an instance of {@code className}, resolving {@code className} in
@@ -91,7 +89,7 @@
      *     method calls to.
      * @return an InvocationHandlerWithDelegateGetter wrapping {@code delegate}
      */
-    @TargetApi(Build.VERSION_CODES.KITKAT)
+    @RequiresApi(Build.VERSION_CODES.KITKAT)
     @Nullable
     public static InvocationHandler createInvocationHandlerFor(@Nullable final Object delegate) {
         if (delegate == null) return null;
@@ -111,7 +109,7 @@
      * @return an array of InvocationHandlerWithDelegateGetter instances, each delegating to
      *     the corresponding member of {@code delegates}.
      */
-    @TargetApi(Build.VERSION_CODES.KITKAT)
+    @RequiresApi(Build.VERSION_CODES.KITKAT)
     @Nullable
     public static InvocationHandler[] createInvocationHandlersForArray(
             @Nullable final Object[] delegates) {
@@ -148,7 +146,7 @@
      * This allows us to pass InvocationHandlers across the support library boundary and later
      * unwrap the objects used as delegates within those InvocationHandlers.
      */
-    @TargetApi(Build.VERSION_CODES.KITKAT)
+    @RequiresApi(Build.VERSION_CODES.KITKAT)
     private static class InvocationHandlerWithDelegateGetter implements InvocationHandler {
         private final Object mDelegate;
 
diff --git a/src/org/chromium/support_lib_boundary/util/Features.java b/src/org/chromium/support_lib_boundary/util/Features.java
index 40cd85b..d3a5039 100644
--- a/src/org/chromium/support_lib_boundary/util/Features.java
+++ b/src/org/chromium/support_lib_boundary/util/Features.java
@@ -47,6 +47,9 @@
     // WebViewCompat.startSafeBrowsing
     public static final String START_SAFE_BROWSING = "START_SAFE_BROWSING";
 
+    // WebViewCompat.setSafeBrowsingAllowlist
+    public static final String SAFE_BROWSING_ALLOWLIST = "SAFE_BROWSING_ALLOWLIST";
+
     // WebViewCompat.setSafeBrowsingWhitelist
     public static final String SAFE_BROWSING_WHITELIST = "SAFE_BROWSING_WHITELIST";
 
@@ -173,4 +176,10 @@
     // WebViewCompat.addWebMessageListener
     // WebViewCompat.removeWebMessageListener
     public static final String WEB_MESSAGE_LISTENER = "WEB_MESSAGE_LISTENER";
+
+    // WebViewProviderFactoryAdapter.setSupportLibraryVersion
+    public static final String SET_SUPPORT_LIBRARY_VERSION = "SET_SUPPORT_LIBRARY_VERSION";
+
+    // WebViewCompat.addDocumentStartJavascript
+    public static final String DOCUMENT_START_SCRIPT = "DOCUMENT_START_SCRIPT:1";
 }