Show visible feedback that private browsing not supported.

As well as a message in logcat, provide visual feedback that the
WebView no longer supports private browsing when an app attempts
to create one.

Bug: 7390806
Change-Id: I9c66bcf9e55f4c085475ab462a0d6e846c55e4dc
diff --git a/chromium/java/com/android/webview/chromium/WebViewChromium.java b/chromium/java/com/android/webview/chromium/WebViewChromium.java
index a318b45..8144b26 100644
--- a/chromium/java/com/android/webview/chromium/WebViewChromium.java
+++ b/chromium/java/com/android/webview/chromium/WebViewChromium.java
@@ -50,6 +50,7 @@
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
 import android.webkit.WebViewProvider;
+import android.widget.TextView;
 
 import org.chromium.android_webview.AwBrowserContext;
 import org.chromium.android_webview.AwContents;
@@ -136,6 +137,10 @@
                 // user data cannot leak through misuse of a non-privateBrowing WebView instance.
                 // Can't just null out mAwContents as we never null-check it before use.
                 mAwContents.destroy();
+                TextView warningLabel = new TextView(mWebView.getContext());
+                warningLabel.setText(mWebView.getContext().getString(
+                        com.android.internal.R.string.webviewchromium_private_browsing_warning));
+                mWebView.addView(warningLabel);
             }
         }
 
diff --git a/chromium/overlay/frameworks/base/core/res/res/values/chromium-resources.xml b/chromium/overlay/frameworks/base/core/res/res/values/chromium-resources.xml
index e6e0bd8..195c9b6 100644
--- a/chromium/overlay/frameworks/base/core/res/res/values/chromium-resources.xml
+++ b/chromium/overlay/frameworks/base/core/res/res/values/chromium-resources.xml
@@ -69,6 +69,7 @@
   <add-resource type="string" name="webviewchromium_media_player_loading_video" />
   <add-resource type="string" name="webviewchromium_month_picker_dialog_title" />
   <add-resource type="string" name="webviewchromium_opening_file_error" />
+  <add-resource type="string" name="webviewchromium_private_browsing_warning" />
   <add-resource type="string" name="webviewchromium_time_picker_dialog_am" />
   <add-resource type="string" name="webviewchromium_time_picker_dialog_hour_minute_separator" />
   <add-resource type="string" name="webviewchromium_time_picker_dialog_minute_second_separator" />
diff --git a/chromium/overlay/frameworks/base/core/res/res/values/chromium-symbols.xml b/chromium/overlay/frameworks/base/core/res/res/values/chromium-symbols.xml
index 13a1718..0d56ad9 100644
--- a/chromium/overlay/frameworks/base/core/res/res/values/chromium-symbols.xml
+++ b/chromium/overlay/frameworks/base/core/res/res/values/chromium-symbols.xml
@@ -71,6 +71,7 @@
   <java-symbol type="string" name="webviewchromium_media_player_loading_video" />
   <java-symbol type="string" name="webviewchromium_month_picker_dialog_title" />
   <java-symbol type="string" name="webviewchromium_opening_file_error" />
+  <java-symbol type="string" name="webviewchromium_private_browsing_warning" />
   <java-symbol type="string" name="webviewchromium_time_picker_dialog_am" />
   <java-symbol type="string" name="webviewchromium_time_picker_dialog_hour_minute_separator" />
   <java-symbol type="string" name="webviewchromium_time_picker_dialog_minute_second_separator" />
diff --git a/chromium/overlay/frameworks/base/core/res/res/values/strings.xml b/chromium/overlay/frameworks/base/core/res/res/values/strings.xml
index de60313..5a87e2f 100644
--- a/chromium/overlay/frameworks/base/core/res/res/values/strings.xml
+++ b/chromium/overlay/frameworks/base/core/res/res/values/strings.xml
@@ -98,4 +98,8 @@
 
     <!--Toast when the browser is unable to open a file for upload. [CHAR-LIMIT=32] -->
     <string name="webviewchromium_opening_file_error">Failed to open selected file</string>
+
+    <!-- Warning shown when the app tries to create a private browsing WebView,
+         which is not supported. [CHAR-LIMIT=NONE] -->
+    <string name="webviewchromium_private_browsing_warning">This functionality is not supported in this version of Android.</string>
 </resources>