Add compositor support for half-float RGBA buffers and textures

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 126 matching lines @@
   void DoDrawPolygon(const DrawPolygon& poly,
                      DrawingFrame* frame,
                      const gfx::Rect& render_pass_scissor,
                      bool use_render_pass_scissor);
 
   const FilterOperations* FiltersForPass(int render_pass_id) const;
   const FilterOperations* BackgroundFiltersForPass(int render_pass_id) const;
 
   // Private interface implemented by subclasses for use by DirectRenderer.
   virtual bool CanPartialSwap() = 0;
+  virtual ResourceFormat BackbufferFormat() const = 0;
   virtual void BindFramebufferToOutputSurface(DrawingFrame* frame) = 0;
   virtual bool BindFramebufferToTexture(DrawingFrame* frame,
                                         const ScopedResource* resource) = 0;
   virtual void SetScissorTestRect(const gfx::Rect& scissor_rect) = 0;
   virtual void PrepareSurfaceForPass(
       DrawingFrame* frame,
       SurfaceInitializationMode initialization_mode,
       const gfx::Rect& render_pass_scissor) = 0;
   // |clip_region| is a (possibly null) pointer to a quad in the same
   // space as the quad. When non-null only the area of the quad that overlaps
@@ skipping 67 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_