OffscreenPreRaster and its plumbings

android_webview/native/aw_settings.cc

Index: android_webview/native/aw_settings.cc
diff --git a/android_webview/native/aw_settings.cc b/android_webview/native/aw_settings.cc
index 6589e960b3c245a7cc348270c0ca982d352ca1d4..4b019aa56123e6d3fe3fc61e1057951109b95143 100644
--- a/android_webview/native/aw_settings.cc
+++ b/android_webview/native/aw_settings.cc
@@ -209,6 +209,15 @@ void AwSettings::UpdateRendererPreferencesLocked(JNIEnv* env, jobject obj) {
     host->SyncRendererPrefs();
 }
 
+void AwSettings::UpdateOffscreenPreRasterLocked(JNIEnv* env,
+                                                jobject obj,
+                                                jboolean enabled) {
+  AwContents* contents = AwContents::FromWebContents(web_contents());
+  if (contents) {
+    contents->SetOffscreenPreRaster(enabled);

[boliu, 2015/02/21 00:03:00]

This breaks the existing pattern that native reads the state from java (instead
of passing it in the post task). So add a @CalledByNative
getOffscreenPreRasterLocked here and use that here.

Then call this method from UpdateEverythingLocked

(I believe this is all to support using the setting object without binding to a
thread as the UI thread)

[hush (inactive), 2015/02/21 00:27:03]

Done.

+  }
+}
+
 void AwSettings::RenderViewCreated(content::RenderViewHost* render_view_host) {
   // A single WebContents can normally have 0 to many RenderViewHost instances
   // associated with it.