Clear ui::Layer damaged_region_ after commit.

ui/compositor/layer.h

 // Copyright (c) 2012 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.
 
 #ifndef UI_COMPOSITOR_LAYER_H_
 #define UI_COMPOSITOR_LAYER_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 316 matching lines @@
   bool SchedulePaint(const gfx::Rect& invalid_rect);
 
   // Schedules a redraw of the layer tree at the compositor.
   // Note that this _does not_ invalidate any region of this layer; use
   // SchedulePaint() for that.
   void ScheduleDraw();
 
   // Uses damaged rectangles recorded in |damaged_region_| to invalidate the
   // |cc_layer_|.
   void SendDamagedRects();
-  void ClearDamagedRects();
 
   const cc::Region& damaged_region() const { return damaged_region_; }
 
   void CompleteAllAnimations();
 
   // Suppresses painting the content by disconnecting |delegate_|.
   void SuppressPaint();
 
   // Notifies the layer that the device scale factor has changed.
   void OnDeviceScaleFactorChanged(float device_scale_factor);
@@ skipping 25 matching lines @@
   // LayerClient
   std::unique_ptr<base::trace_event::ConvertableToTraceFormat> TakeDebugInfo(
       cc::Layer* layer) override;
 
   // Whether this layer has animations waiting to get sent to its cc::Layer.
   bool HasPendingThreadedAnimationsForTesting() const;
 
   // Triggers a call to SwitchToLayer.
   void SwitchCCLayerForTest();
 
+  const cc::Region* damaged_region_for_testing() const {

[danakj, 2016/05/31 19:53:15]

const Region&?

+    return &damaged_region_;
+  }
+
  private:
   friend class LayerOwner;
 
   void CollectAnimators(std::vector<scoped_refptr<LayerAnimator> >* animators);
 
   // Stacks |child| above or below |other|.  Helper method for StackAbove() and
   // StackBelow().
   void StackRelativeTo(Layer* child, Layer* other, bool above);
 
   bool ConvertPointForAncestor(const Layer* ancestor, gfx::Point* point) const;
@@ skipping 50 matching lines @@
 
   gfx::Rect bounds_;
   gfx::Vector2dF subpixel_position_offset_;
 
   // Visibility of this layer. See SetVisible/IsDrawn for more details.
   bool visible_;
 
   bool fills_bounds_opaquely_;
   bool fills_bounds_completely_;
 
+  // Union of damaged rects, in layer space, that SetNeedsDisplayRect should
+  // be called on.
+  cc::Region damaged_region_;
+
   // Union of damaged rects, in layer space, to be used when compositor is ready
   // to paint the content.
-  cc::Region damaged_region_;
+  cc::Region paint_region_;
 
   int background_blur_radius_;
 
   // Several variables which will change the visible representation of
   // the layer.
   float layer_saturation_;
   float layer_brightness_;
   float layer_grayscale_;
   bool layer_inverted_;
 
@@ skipping 56 matching lines @@
   // The texture scale.
   float texture_x_scale_;
   float texture_y_scale_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_LAYER_H_