Allow switching DirectCompositionSurfaceWin between drawing modes.

cc/output/direct_renderer.h

 // Copyright 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 CC_OUTPUT_DIRECT_RENDERER_H_
 #define CC_OUTPUT_DIRECT_RENDERER_H_
 
 #include <memory>
 #include <unordered_map>
 #include <vector>
@@ skipping 148 matching lines @@
   // a render pass (e.g. applying a filter directly to the tile quad)
   // return that quad, otherwise return null.
   virtual const TileDrawQuad* CanPassBeDrawnDirectly(const RenderPass* pass);
   virtual void FinishDrawingQuadList() {}
   virtual bool FlippedFramebuffer() const = 0;
   virtual void EnsureScissorTestEnabled() = 0;
   virtual void EnsureScissorTestDisabled() = 0;
   virtual void DidChangeVisibility() = 0;
   virtual void CopyCurrentRenderPassToBitmap(
       std::unique_ptr<CopyOutputRequest> request) = 0;
+  virtual void SetEnableDCLayers(bool enable) = 0;
 
   gfx::Size surface_size_for_swap_buffers() const {
     return reshape_surface_size_;
   }
 
   const RendererSettings* const settings_;
   OutputSurface* const output_surface_;
   ResourceProvider* const resource_provider_;
   // This can be replaced by test implementations.
   std::unique_ptr<OverlayProcessor> overlay_processor_;
 
   // Whether it's valid to SwapBuffers with an empty rect. Trivially true when
   // using partial swap.
   bool allow_empty_swap_ = false;
   // Whether partial swap can be used.
   bool use_partial_swap_ = false;
   // Whether overdraw feedback is enabled and can be used.
   bool overdraw_feedback_ = false;
-  // Whether the SetDrawRectangle command is in use.
-  bool use_set_draw_rectangle_ = false;
+  // Whether the SetDrawRectangle and EnableDCLayers commands are in
+  // use.
+  bool supports_dc_layers_ = false;
+  // Whether the output surface is actually using DirectComposition.
+  bool using_dc_layers_ = false;
+  // This counts the number of draws since the last time
+  // DirectComposition layers needed to be used.
+  int frames_since_using_dc_layers_ = 0;
 
   // TODO(danakj): Just use a vector of pairs here? Hash map is way overkill.
   std::unordered_map<int, std::unique_ptr<ScopedResource>>
       render_pass_textures_;
   std::unordered_map<int, TileDrawQuad> render_pass_bypass_quads_;
 
   RenderPassFilterList render_pass_filters_;
   RenderPassFilterList render_pass_background_filters_;
 
   bool visible_ = false;
@@ skipping 38 matching lines @@
   gfx::ColorSpace reshape_device_color_space_;
   bool reshape_has_alpha_ = false;
   bool reshape_use_stencil_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(DirectRenderer);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_DIRECT_RENDERER_H_