cc: Implement overdraw feedback debugging feature.

cc/test/pixel_test_output_surface.cc

 // Copyright 2013 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/test/pixel_test_output_surface.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "cc/output/output_surface_client.h"
 #include "cc/output/output_surface_frame.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "ui/gfx/transform.h"
 
 namespace cc {
 
 PixelTestOutputSurface::PixelTestOutputSurface(
     scoped_refptr<ContextProvider> context_provider,
     bool flipped_output_surface)
     : OutputSurface(std::move(context_provider)), weak_ptr_factory_(this) {
   capabilities_.flipped_output_surface = flipped_output_surface;
+  capabilities_.supports_stencil = true;
 }
 
 PixelTestOutputSurface::PixelTestOutputSurface(
     std::unique_ptr<SoftwareOutputDevice> software_device)
-    : OutputSurface(std::move(software_device)), weak_ptr_factory_(this) {}
+    : OutputSurface(std::move(software_device)), weak_ptr_factory_(this) {
+  capabilities_.supports_stencil = true;
+}
 
 PixelTestOutputSurface::~PixelTestOutputSurface() = default;
 
 void PixelTestOutputSurface::BindToClient(OutputSurfaceClient* client) {
   client_ = client;
 }
 
 void PixelTestOutputSurface::EnsureBackbuffer() {}
 
 void PixelTestOutputSurface::DiscardBackbuffer() {}
 
 void PixelTestOutputSurface::BindFramebuffer() {
   context_provider()->ContextGL()->BindFramebuffer(GL_FRAMEBUFFER, 0);
 }
 
 void PixelTestOutputSurface::Reshape(const gfx::Size& size,
                                      float device_scale_factor,
                                      const gfx::ColorSpace& color_space,
-                                     bool has_alpha) {
+                                     bool has_alpha,
+                                     bool use_stencil) {
+  // External stencil test cannot be tested at the same time as |use_stencil|.
+  DCHECK(!use_stencil || !external_stencil_test_);
   if (context_provider()) {
     context_provider()->ContextGL()->ResizeCHROMIUM(
         size.width(), size.height(), device_scale_factor, has_alpha);
   } else {
     software_device()->Resize(size, device_scale_factor);
   }
 }
 
 bool PixelTestOutputSurface::HasExternalStencilTest() const {
   return external_stencil_test_;
@@ skipping 29 matching lines @@
 }
 
 uint32_t PixelTestOutputSurface::GetFramebufferCopyTextureFormat() {
   // This format will work if the |context_provider| has an RGB or RGBA
   // framebuffer. For now assume tests do not want/care about alpha in
   // the root render pass.
   return GL_RGB;
 }
 
 }  // namespace cc