cc: Make PrepareToDraw return an enum for why it aborts

cc/layers/texture_layer_unittest.cc

 // 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.
 
 #include "cc/layers/texture_layer.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 1384 matching lines @@
         NOTREACHED();
         break;
     }
   }
 
   virtual void BeginCommitOnThread(LayerTreeHostImpl* host_impl) OVERRIDE {
     base::AutoLock lock(lock_);
     expected_used_textures_on_draw_ = expected_used_textures_on_commit_;
   }
 
-  virtual bool PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
-                                     LayerTreeHostImpl::FrameData* frame_data,
-                                     bool result) OVERRIDE {
+  virtual DrawSwapReadbackResult::DrawResult PrepareToDrawOnThread(
+      LayerTreeHostImpl* host_impl,
+      LayerTreeHostImpl::FrameData* frame_data,
+      DrawSwapReadbackResult::DrawResult draw_result) OVERRIDE {
     ContextForImplThread(host_impl)->ResetUsedTextures();
-    return true;
+    return DrawSwapReadbackResult::DID_DRAW;
   }
 
   virtual void SwapBuffersOnThread(LayerTreeHostImpl* host_impl,
                                    bool result) OVERRIDE {
     ASSERT_TRUE(result);
     EXPECT_EQ(expected_used_textures_on_draw_,
               ContextForImplThread(host_impl)->NumUsedTextures());
   }
 
   virtual void AfterTest() OVERRIDE {}
@@ skipping 121 matching lines @@
         break;
     }
   }
 
   virtual void BeginCommitOnThread(LayerTreeHostImpl* host_impl) OVERRIDE {
     ASSERT_TRUE(proxy()->IsMainThreadBlocked());
     // This is the only texture that can be drawn this frame.
     expected_texture_on_draw_ = texture_;
   }
 
-  virtual bool PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
-                                     LayerTreeHostImpl::FrameData* frame_data,
-                                     bool result) OVERRIDE {
+  virtual DrawSwapReadbackResult::DrawResult PrepareToDrawOnThread(
+      LayerTreeHostImpl* host_impl,
+      LayerTreeHostImpl::FrameData* frame_data,
+      DrawSwapReadbackResult::DrawResult draw_result) OVERRIDE {
     ContextForImplThread(host_impl)->ResetUsedTextures();
-    return true;
+    return DrawSwapReadbackResult::DID_DRAW;
   }
 
   virtual void SwapBuffersOnThread(LayerTreeHostImpl* host_impl,
                                    bool result) OVERRIDE {
     ASSERT_TRUE(result);
     TestWebGraphicsContext3D* context = ContextForImplThread(host_impl);
     int used_textures = context->NumUsedTextures();
     switch (host_impl->active_tree()->source_frame_number()) {
       case 0:
         EXPECT_EQ(1, used_textures);
@@ skipping 409 matching lines @@
     root->AddChild(texture_layer_);
 
     layer_tree_host()->SetRootLayer(root);
     LayerTreeTest::SetupTree();
   }
 
   virtual void BeginTest() OVERRIDE {
     PostSetNeedsCommitToMainThread();
   }
 
-  virtual bool PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
-                                     LayerTreeHostImpl::FrameData* frame_data,
-                                     bool result) OVERRIDE {
+  virtual DrawSwapReadbackResult::DrawResult PrepareToDrawOnThread(
+      LayerTreeHostImpl* host_impl,
+      LayerTreeHostImpl::FrameData* frame_data,
+      DrawSwapReadbackResult::DrawResult draw_result) OVERRIDE {
     LayerImpl* root = host_impl->RootLayer();
     TextureLayerImpl* texture_layer =
         static_cast<TextureLayerImpl*>(root->children()[0]);
     if (++draw_count_ == 1)
       EXPECT_EQ(0u, texture_layer->texture_id());
     else
       EXPECT_EQ(1u, texture_layer->texture_id());
-    return true;
+    return DrawSwapReadbackResult::DID_DRAW;
   }
 
   virtual void DidCommitAndDrawFrame() OVERRIDE {
     EndTest();
   }
 
   virtual void AfterTest() OVERRIDE {}
 
  private:
   scoped_refptr<TextureLayer> texture_layer_;
@@ skipping 145 matching lines @@
   int callback_count_;
   scoped_refptr<Layer> root_;
   scoped_refptr<TextureLayer> layer_;
 };
 
 SINGLE_AND_MULTI_THREAD_DIRECT_RENDERER_TEST_F(
     TextureLayerWithMailboxImplThreadDeleted);
 
 }  // namespace
 }  // namespace cc