Hide fullscreen rotation jank

ui/android/view_android.h

Index: ui/android/view_android.h
diff --git a/ui/android/view_android.h b/ui/android/view_android.h
index c88d878629c0373d9c5459c1c3c227bd3e40ebe0..5b2468f630bcd1df0705dbc1e080b4e6f27ab487 100644
--- a/ui/android/view_android.h
+++ b/ui/android/view_android.h
@@ -130,6 +130,8 @@ class UI_ANDROID_EXPORT ViewAndroid {
   // Sets the layout relative to parent. Used to do hit testing against events.
   void SetLayout(LayoutParams params);
 
+  void ClearThumbnailPlaceholder();

[boliu, 2017/07/05 17:39:48]

this has nothing to do with ViewAndroid tree

and feels like a layering violation too, since thumbnail placeholder is an
entirely chrome/ concept, so lower layers like content/ or ui/ should not know
about it.

shouldn't chrome layer know to do this already, whenever it enters fullscreen?
If that doesn't work, then need to name this to "what happened" rather than "do
this", maybe something like DidEvictFrameForFullscreenTransition

+
   bool StartDragAndDrop(const base::android::JavaRef<jstring>& jtext,
                         const base::android::JavaRef<jobject>& jimage);