cc: Toward merging DrawFrame and SwapBuffers in DelegatingRenderer.

cc/output/delegating_renderer_unittest.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/output/delegating_renderer.h"
 
 #include <stdint.h>
 
 #include "cc/test/fake_output_surface.h"
 #include "cc/test/layer_tree_test.h"
 #include "cc/test/render_pass_test_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
 
 class DelegatingRendererTest : public LayerTreeTest {};
 
 class DelegatingRendererTestDraw : public DelegatingRendererTest {
  public:
   void BeginTest() override {
     layer_tree()->SetPageScaleFactorAndLimits(1.f, 0.5f, 4.f);
     PostSetNeedsCommitToMainThread();
   }
 
   void AfterTest() override {}
 
-  void DrawLayersOnThread(LayerTreeHostImpl* host_impl) override {
+  DrawResult PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
+                                   LayerTreeHostImpl::FrameData* frame_data,
+                                   DrawResult draw_result) override {
     EXPECT_EQ(0, num_swaps_);
     drawn_viewport_ = host_impl->DeviceViewport();
+    return draw_result;

[enne (OOO), 2016/09/07 18:05:51]

Previously this wouldn't have been called if the DrawResult was that it wasn't
going to draw? Maybe you should DCHECK draw result?

Or maybe drawn_viewport_ means something else here other than actually drawn?

[danakj, 2016/09/07 18:42:15]

Um, well, its the size of the viewport we're drawing this frame. I can dcheck
the draw result sure.

[danakj, 2016/09/07 18:52:00]

Done.

   }
 
   void DisplayReceivedCompositorFrameOnThread(
       const CompositorFrame& frame) override {
     EXPECT_EQ(1, ++num_swaps_);
 
     DelegatedFrameData* last_frame_data = frame.delegated_frame_data.get();
     ASSERT_TRUE(frame.delegated_frame_data);
     EXPECT_FALSE(frame.gl_frame_data);
     EXPECT_EQ(drawn_viewport_,
@@ skipping 50 matching lines @@
     // updated accordingly.
     EXPECT_EQ(22u, frame.delegated_frame_data->resource_list.size());
 
     EndTest();
   }
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(DelegatingRendererTestResources);
 
 }  // namespace cc