Hook up ui::Compositor to Display's BeginFrameSource

cc/surfaces/display_scheduler_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 "cc/surfaces/display_scheduler.h"
 
 #include "base/logging.h"
 #include "base/test/null_task_runner.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 10 matching lines @@
 class FakeDisplaySchedulerClient : public DisplaySchedulerClient {
  public:
   FakeDisplaySchedulerClient() : draw_and_swap_count_(0) {}
 
   ~FakeDisplaySchedulerClient() override {}
 
   bool DrawAndSwap() override {
     draw_and_swap_count_++;
     return true;
   }
+  void UpdateSchedulerBeginFrameSource(BeginFrameSource* source) override {}
 
   void Reset() { draw_and_swap_count_ = 0; }
 
   int draw_and_swap_count() const { return draw_and_swap_count_; }
 
  protected:
   int draw_and_swap_count_;
 };
 
 class TestDisplayScheduler : public DisplayScheduler {
@@ skipping 396 matching lines @@
 
   scheduler_->SetRootSurfaceResourcesLocked(true);
   EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());
 
   scheduler_->OutputSurfaceLost();
   EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());
 }
 
 }  // namespace
 }  // namespace cc