cc: Make PrepareToDraw return an enum for why it aborts

cc/test/layer_tree_test.cc

 // Copyright 2011 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/layer_tree_test.h"
 
 #include "base/command_line.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_registrar.h"
 #include "cc/animation/layer_animation_controller.h"
@@ skipping 17 matching lines @@
 #include "testing/gmock/include/gmock/gmock.h"
 #include "ui/gfx/frame_time.h"
 #include "ui/gfx/size_conversions.h"
 
 namespace cc {
 
 TestHooks::TestHooks() {}
 
 TestHooks::~TestHooks() {}
 
-bool TestHooks::PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
-                                      LayerTreeHostImpl::FrameData* frame_data,
-                                      bool result) {
-  return true;
+DrawSwapReadbackResult::DrawResult TestHooks::PrepareToDrawOnThread(
+    LayerTreeHostImpl* host_impl,
+    LayerTreeHostImpl::FrameData* frame_data,
+    DrawSwapReadbackResult::DrawResult draw_result) {
+  return draw_result;
 }
 
 base::TimeDelta TestHooks::LowFrequencyAnimationInterval() const {
   return base::TimeDelta::FromMilliseconds(16);
 }
 
 // Adapts LayerTreeHostImpl for test. Runs real code, then invokes test hooks.
 class LayerTreeHostImplForTesting : public LayerTreeHostImpl {
  public:
   static scoped_ptr<LayerTreeHostImplForTesting> Create(
@@ skipping 42 matching lines @@
   virtual void CommitComplete() OVERRIDE {
     LayerTreeHostImpl::CommitComplete();
     test_hooks_->CommitCompleteOnThread(this);
 
     if (!settings().impl_side_painting) {
       test_hooks_->WillActivateTreeOnThread(this);
       test_hooks_->DidActivateTreeOnThread(this);
     }
   }
 
-  virtual bool PrepareToDraw(FrameData* frame,
-                             const gfx::Rect& damage_rect) OVERRIDE {
-    bool result = LayerTreeHostImpl::PrepareToDraw(frame, damage_rect);
-    if (!test_hooks_->PrepareToDrawOnThread(this, frame, result))
-      result = false;
-    return result;
+  virtual DrawSwapReadbackResult::DrawResult PrepareToDraw(
+      FrameData* frame,
+      const gfx::Rect& damage_rect) OVERRIDE {
+    DrawSwapReadbackResult::DrawResult draw_result =
+        LayerTreeHostImpl::PrepareToDraw(frame, damage_rect);
+    return test_hooks_->PrepareToDrawOnThread(this, frame, draw_result);
   }
 
   virtual void DrawLayers(FrameData* frame,
                           base::TimeTicks frame_begin_time) OVERRIDE {
     LayerTreeHostImpl::DrawLayers(frame, frame_begin_time);
     test_hooks_->DrawLayersOnThread(this);
   }
 
   virtual bool SwapBuffers(const LayerTreeHostImpl::FrameData& frame) OVERRIDE {
     bool result = LayerTreeHostImpl::SwapBuffers(frame);
@@ skipping 585 matching lines @@
     const {
   if (impl->pending_tree())
     return impl->pending_tree()->source_frame_number();
   if (impl->active_tree())
     return impl->active_tree()->source_frame_number();
   // Source frames start at 0, so this is invalid.
   return -1;
 }
 
 }  // namespace cc