Only gather transparent regions inside their own view bounds in views that might have children exte…

chrome/android/java/src/org/chromium/chrome/browser/util/ViewUtils.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.util;
 
 import android.graphics.Canvas;
+import android.graphics.Region;
 import android.view.View;
 import android.view.ViewGroup;
 
 /**
  * View-related utility methods.
  */
 public class ViewUtils {
+    private static final int[] sLocationTmp = new int[2];
+
     /**
      * Invalidates a view and all of its descendants.
      */
     private static void recursiveInvalidate(View view) {
         view.invalidate();
         if (view instanceof ViewGroup) {
             ViewGroup group = (ViewGroup) view;
             int childCount = group.getChildCount();
             for (int i = 0; i < childCount; i++) {
                 View child = group.getChildAt(i);
@@ skipping 44 matching lines @@
     public static void getRelativeDrawPosition(View rootView, View childView, int[] outPosition) {
         assert outPosition.length == 2;
         outPosition[0] = 0;
         outPosition[1] = 0;
         while (childView != null && childView != rootView) {
             outPosition[0] += childView.getX();
             outPosition[1] += childView.getY();
             childView = (View) childView.getParent();
         }
     }
+
+    /**
+     * Helper for overriding {@link View#gatherTransparentRegions()} for views that are fully opaque
+     * and have children extending beyond their bounds. If the transparent region optimization is
+     * turned on (which is the case whenever the view hierarchy contains a SurfaceView somewhere),
+     * the children might otherwise confuse the SurfaceFlinger.
+     */
+    public static void gatherTransparentRegionsForOpaqueView(View view, Region region) {
+        view.getLocationInWindow(sLocationTmp);
+        region.op(sLocationTmp[0], sLocationTmp[1],
+                sLocationTmp[0] + view.getRight() - view.getLeft(),
+                sLocationTmp[1] + view.getBottom() - view.getTop(), Region.Op.DIFFERENCE);
+    }
 }