android webview: setShouldReuseGlobalForUnownedMainFrame

android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java

Index: android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java
diff --git a/android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java b/android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java
index eea404c5132bbf65eae6d31ac71892c995f7888b..c5a1f3d11811c664799d9ab73047922c7b13711f 100644
--- a/android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java
+++ b/android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java
@@ -234,11 +234,13 @@ class WebViewChromium implements WebViewProvider, WebViewProvider.ScrollDelegate
         final boolean isAccessFromFileURLsGrantedByDefault =
                 mAppTargetSdkVersion < Build.VERSION_CODES.JELLY_BEAN;
         final boolean areLegacyQuirksEnabled = mAppTargetSdkVersion < Build.VERSION_CODES.KITKAT;
+        final boolean allowEmptyDocumentPersistence = mAppTargetSdkVersion <= Build.VERSION_CODES.M;

[boliu, 2016/04/05 17:53:49]

is this safe?

[sgurun-gerrit only, 2016/04/05 18:24:15]

I think that is the best we can do at the moment.Another alternative is always
setting allowEmptyDocumentPersistence to true here, and in the internal glue
layer, test against Build.VERSION_CODES.N.

I still prefer this one.

 
         mContentsClientAdapter =
                 new WebViewContentsClientAdapter(mWebView, mContext, mFactory.getWebViewDelegate());
-        mWebSettings = new ContentSettingsAdapter(new AwSettings(
-                mContext, isAccessFromFileURLsGrantedByDefault, areLegacyQuirksEnabled));
+        mWebSettings = new ContentSettingsAdapter(
+                new AwSettings(mContext, isAccessFromFileURLsGrantedByDefault,
+                        areLegacyQuirksEnabled, allowEmptyDocumentPersistence));
 
         if (mAppTargetSdkVersion < Build.VERSION_CODES.LOLLIPOP) {
             // Prior to Lollipop we always allowed third party cookies and mixed content.