cc: Implement overdraw feedback debugging feature.

cc/output/output_surface.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_OUTPUT_SURFACE_H_
 #define CC_OUTPUT_OUTPUT_SURFACE_H_
 
 #include <deque>
 #include <memory>
 
@@ skipping 26 matching lines @@
  public:
   struct Capabilities {
     Capabilities() = default;
 
     int max_frames_pending = 1;
     // Whether this output surface renders to the default OpenGL zero
     // framebuffer or to an offscreen framebuffer.
     bool uses_default_gl_framebuffer = true;
     // Whether this OutputSurface is flipped or not.
     bool flipped_output_surface = false;
+    // Whether this OutputSurface supports stencil operations or not.
+    // Note: HasExternalStencilTest() must return false when an output surface
+    // has been configured for stencil usage.
+    bool supports_stencil = false;
   };
 
   // Constructor for GL-based compositing.
   explicit OutputSurface(scoped_refptr<ContextProvider> context_provider);
   // Constructor for software compositing.
   explicit OutputSurface(std::unique_ptr<SoftwareOutputDevice> software_device);
   // Constructor for Vulkan-based compositing.
   explicit OutputSurface(
       scoped_refptr<VulkanContextProvider> vulkan_context_provider);
 
@@ skipping 30 matching lines @@
 
   // Get the texture for the main image's overlay.
   virtual unsigned GetOverlayTextureId() const = 0;
 
   // If this returns true, then the surface will not attempt to draw.
   virtual bool SurfaceIsSuspendForRecycle() const = 0;
 
   virtual void Reshape(const gfx::Size& size,
                        float device_scale_factor,
                        const gfx::ColorSpace& color_space,
-                       bool has_alpha) = 0;
+                       bool has_alpha,
+                       bool use_stencil) = 0;
 
   virtual bool HasExternalStencilTest() const = 0;
   virtual void ApplyExternalStencil() = 0;
 
   // Gives the GL internal format that should be used for calling CopyTexImage2D
   // when the framebuffer is bound via BindFramebuffer().
   virtual uint32_t GetFramebufferCopyTextureFormat() = 0;
 
   // Swaps the current backbuffer to the screen. For successful swaps, the
   // implementation must call OutputSurfaceClient::DidReceiveSwapBuffersAck()
   // after returning from this method in order to unblock the next frame.
   virtual void SwapBuffers(OutputSurfaceFrame frame) = 0;
 
  protected:
   struct OutputSurface::Capabilities capabilities_;
   scoped_refptr<ContextProvider> context_provider_;
   scoped_refptr<VulkanContextProvider> vulkan_context_provider_;
   std::unique_ptr<SoftwareOutputDevice> software_device_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(OutputSurface);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_OUTPUT_SURFACE_H_