Improve transition between opaque and translucent compositor views.

chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java

 // Copyright 2015 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.chrome.browser.compositor;
 
 import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Paint;
 import android.graphics.Rect;
 import android.graphics.RectF;
 import android.os.Bundle;
 import android.os.Handler;
 import android.support.v4.view.ViewCompat;
 import android.support.v4.view.accessibility.AccessibilityEventCompat;
 import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat;
 import android.support.v4.widget.ExploreByTouchHelper;
 import android.util.AttributeSet;
 import android.util.Pair;
 import android.view.DragEvent;
 import android.view.MotionEvent;
-import android.view.SurfaceView;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.accessibility.AccessibilityEvent;
 import android.widget.FrameLayout;
 
 import org.chromium.base.SysUtils;
 import org.chromium.base.TraceEvent;
 import org.chromium.base.annotations.SuppressFBWarnings;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.compositor.Invalidator.Client;
@@ skipping 364 matching lines @@
     }
 
     /**
      * @return The {@link LayoutManager} associated with this view.
      */
     public LayoutManager getLayoutManager() {
         return mLayoutManager;
     }
 
     /**
-     * @return The SurfaceView used by the Compositor.
+     * @return The SurfaceView proxy used by the Compositor.
      */
-    public SurfaceView getSurfaceView() {
+    public View getCompositorView() {
         return mCompositorView;
     }
 
     private View getActiveView() {
         if (mLayoutManager == null || mTabModelSelector == null) return null;
         Tab tab = mTabModelSelector.getCurrentTab();
         return tab != null ? tab.getContentView() : null;
     }
 
     private ContentViewCore getActiveContent() {
@@ skipping 674 matching lines @@
             if (mPixelRect.width() == 0) {
                 mPixelRect.right = mPixelRect.left + 1;
             }
             if (mPixelRect.height() == 0) {
                 mPixelRect.bottom = mPixelRect.top + 1;
             }
             return mPixelRect;
         }
     }
 }