Implement new RPDQ copy logic for CALayer promotion.

cc/output/overlay_processor.cc

 // Copyright 2014 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.
 
 #include "cc/output/overlay_processor.h"
 
 #include "cc/output/output_surface.h"
 #include "cc/output/overlay_strategy_single_on_top.h"
 #include "cc/output/overlay_strategy_underlay.h"
 #include "cc/quads/draw_quad.h"
@@ skipping 34 matching lines @@
 
   if (!ProcessForCALayerOverlays(resource_provider,
                                  gfx::RectF(render_pass->output_rect),
                                  render_pass->quad_list, ca_layer_overlays))
     return false;
 
   // CALayer overlays are all-or-nothing. If all quads were replaced with
   // layers then clear the list and remove the backbuffer from the overcandidate
   // list.
   overlay_candidates->clear();
-  render_pass->quad_list.clear();
   overlay_damage_rect_ = render_pass->output_rect;
   *damage_rect = gfx::Rect();
   return true;
 }
 
 void OverlayProcessor::ProcessForOverlays(ResourceProvider* resource_provider,
                                           RenderPass* render_pass,
                                           OverlayCandidateList* candidates,
                                           CALayerOverlayList* ca_layer_overlays,
                                           gfx::Rect* damage_rect) {
@@ skipping 50 matching lines @@
   }
 
   if (this_frame_underlay_rect == previous_frame_underlay_rect_)
     damage_rect->Subtract(this_frame_underlay_rect);
   previous_frame_underlay_rect_ = this_frame_underlay_rect;
 
   damage_rect->Union(output_surface_overlay_damage_rect);
 }
 
 }  // namespace cc