Revert of Remove CompositorObserver::OnCompositingEnded()

ui/compositor/compositor_unittest.cc

 // Copyright 2015 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 <stdint.h>
 
 #include "base/macros.h"
 #include "base/run_loop.h"
 #include "base/test/test_mock_time_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 77 matching lines @@
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 };
 
 class CompositorObserverForLocks : public CompositorObserver {
  public:
   CompositorObserverForLocks() = default;
 
   void OnCompositingDidCommit(Compositor* compositor) override {}
   void OnCompositingStarted(Compositor* compositor,
                             base::TimeTicks start_time) override {}
+  void OnCompositingEnded(Compositor* compositor) override {}
   void OnCompositingLockStateChanged(Compositor* compositor) override {
     changed_ = true;
     locked_ = compositor->IsLocked();
   }
   void OnCompositingShuttingDown(Compositor* compositor) override {}
 
   bool changed() const { return changed_; }
   bool locked() const { return locked_; }
 
   void Reset() { changed_ = false; }
@@ skipping 215 matching lines @@
 #else
 #define MAYBE_CreateAndReleaseOutputSurface CreateAndReleaseOutputSurface
 #endif
 TEST_F(CompositorTestWithMessageLoop, MAYBE_CreateAndReleaseOutputSurface) {
   std::unique_ptr<Layer> root_layer(new Layer(ui::LAYER_SOLID_COLOR));
   root_layer->SetBounds(gfx::Rect(10, 10));
   compositor()->SetRootLayer(root_layer.get());
   compositor()->SetScaleAndSize(1.0f, gfx::Size(10, 10));
   DCHECK(compositor()->IsVisible());
   compositor()->ScheduleDraw();
-  DrawWaiterForTest::WaitForCompositingStarted(compositor());
+  DrawWaiterForTest::WaitForCompositingEnded(compositor());
   compositor()->SetVisible(false);
   EXPECT_EQ(gfx::kNullAcceleratedWidget,
             compositor()->ReleaseAcceleratedWidget());
   compositor()->SetAcceleratedWidget(gfx::kNullAcceleratedWidget);
   compositor()->SetVisible(true);
   compositor()->ScheduleDraw();
-  DrawWaiterForTest::WaitForCompositingStarted(compositor());
+  DrawWaiterForTest::WaitForCompositingEnded(compositor());
   compositor()->SetRootLayer(nullptr);
 }
 
 }  // namespace ui