Implement compositor thread VSync aligned event queue

cc/trees/layer_tree_host_unittest_scroll.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/trees/layer_tree_host.h"
 
 #include "base/location.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 1269 matching lines @@
       const gfx::SizeF& scrollable_size,
       float page_scale_factor,
       float min_page_scale_factor,
       float max_page_scale_factor) override {
     if (!task_runner_->BelongsToCurrentThread()) {
       ADD_FAILURE() << "UpdateRootLayerStateForSynchronousInputHandler called "
                     << " on wrong thread";
     }
   }
 
+  void DeliverInputForBeginFrame() override {
+    if (!task_runner_->BelongsToCurrentThread()) {
+      ADD_FAILURE() << "DeliverInputForBeginFrame called on wrong thread";
+    }
+  }
+
  private:
   base::SingleThreadTaskRunner* task_runner_;
   bool* received_stop_flinging_;
 };
 
 void BindInputHandlerOnCompositorThread(
     const base::WeakPtr<InputHandler>& input_handler,
     ThreadCheckingInputHandlerClient* client) {
   input_handler->BindToClient(client);
 }
@@ skipping 514 matching lines @@
   void WillShutdown() override {}
   void Animate(base::TimeTicks) override {}
   void MainThreadHasStoppedFlinging() override {}
   void UpdateRootLayerStateForSynchronousInputHandler(
       const gfx::ScrollOffset& total_scroll_offset,
       const gfx::ScrollOffset& max_scroll_offset,
       const gfx::SizeF& scrollable_size,
       float page_scale_factor,
       float min_page_scale_factor,
       float max_page_scale_factor) override {}
+  void DeliverInputForBeginFrame() override {}
 };
 
 // This is a regression test, see crbug.com/639046.
 class LayerTreeHostScrollTestElasticOverscroll
     : public LayerTreeHostScrollTest {
  public:
   LayerTreeHostScrollTestElasticOverscroll()
       : num_begin_main_frames_impl_thread_(0),
         scroll_elasticity_helper_(nullptr),
         num_begin_main_frames_main_thread_(0) {}
@@ skipping 396 matching lines @@
 
   const float initial_page_scale_ = 0.5f;
   const float page_scale_update_ = 0.2f;
 };
 
 // The reflected deltas are supported in threaded mode only.
 MULTI_THREAD_TEST_F(LayerTreeHostScrollTestAppliesReflectedDeltas);
 
 }  // namespace
 }  // namespace cc