Make ui::InProcessContextFactory::refresh_rate_ effective.

This change also adds the flag --disable-vsync-for-tests to disable vsync
for test, so the tests will not wait for vsync signal and run as fast as
possible.

Bug: None
Change-Id: I599566dac7381be753ca5dc285caf39cf17cc117
Reviewed-on: https://chromium-review.googlesource.com/661322
Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Peng Huang <penghuang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#501124}

ui/compositor/compositor_switches.cc

@@ -36,6 +36,8 @@ const char kUISlowAnimations[] = "ui-slow-animations";
 // to be done via corner points. See https://goo.gl/Dqig5s
 const char kEnablePixelCanvasRecording[] = "enable-pixel-canvas-recording";
 
+const char kDisableVsyncForTests[] = "disable-vsync-for-tests";
+
 }  // namespace switches
 
 namespace ui {

ui/compositor/compositor_switches.h

@@ -18,6 +18,7 @@ COMPOSITOR_EXPORT extern const char kUIDisableZeroCopy[];
 COMPOSITOR_EXPORT extern const char kUIShowPaintRects[];
 COMPOSITOR_EXPORT extern const char kUISlowAnimations[];
 COMPOSITOR_EXPORT extern const char kEnablePixelCanvasRecording[];
+COMPOSITOR_EXPORT extern const char kDisableVsyncForTests[];
 
 }  // namespace switches
 

ui/compositor/test/in_process_context_factory.cc

@@ -145,6 +145,8 @@ InProcessContextFactory::InProcessContextFactory(
     viz::FrameSinkManagerImpl* frame_sink_manager)
     : frame_sink_id_allocator_(kDefaultClientId),
       use_test_surface_(true),
+      disable_vsync_(base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableVsyncForTests)),
       host_frame_sink_manager_(host_frame_sink_manager),
       frame_sink_manager_(frame_sink_manager) {
   DCHECK(host_frame_sink_manager);
@@ -236,10 +238,21 @@ void InProcessContextFactory::CreateLayerTreeFrameSink(
         base::MakeUnique<DirectOutputSurface>(context_provider);
   }
 
-  std::unique_ptr<viz::DelayBasedBeginFrameSource> begin_frame_source(
-      new viz::DelayBasedBeginFrameSource(
-          base::MakeUnique<viz::DelayBasedTimeSource>(
-              compositor->task_runner().get())));
+  std::unique_ptr<viz::BeginFrameSource> begin_frame_source;
+  if (disable_vsync_) {
+    begin_frame_source = base::MakeUnique<viz::BackToBackBeginFrameSource>(
+        base::MakeUnique<viz::DelayBasedTimeSource>(
+            compositor->task_runner().get()));
+  } else {
+    auto time_source = base::MakeUnique<viz::DelayBasedTimeSource>(
+        compositor->task_runner().get());
+    time_source->SetTimebaseAndInterval(
+        base::TimeTicks(),
+        base::TimeDelta::FromMicroseconds(base::Time::kMicrosecondsPerSecond /
+                                          refresh_rate_));
+    begin_frame_source = base::MakeUnique<viz::DelayBasedBeginFrameSource>(
+        std::move(time_source));
+  }
   auto scheduler = base::MakeUnique<viz::DisplayScheduler>(
       begin_frame_source.get(), compositor->task_runner().get(),
       display_output_surface->capabilities().max_frames_pending);

ui/compositor/test/in_process_context_factory.h

@@ -52,8 +52,8 @@ class InProcessContextFactory : public ContextFactory,
   // using the SharedMainThreadContextProvider.
   void SendOnLostResources();
 
-  // Set refresh rate to 200 to spend less time waiting for BeginFrame when
-  // used for tests.
+  // Set refresh rate will be set to 200 to spend less time waiting for
+  // BeginFrame when used for tests.
   void SetUseFastRefreshRateForTests();
 
   // ContextFactory implementation.
@@ -104,6 +104,7 @@ class InProcessContextFactory : public ContextFactory,
   cc::TestTaskGraphRunner task_graph_runner_;
   viz::FrameSinkIdAllocator frame_sink_id_allocator_;
   bool use_test_surface_;
+  bool disable_vsync_ = false;
   double refresh_rate_ = 60.0;
   viz::HostFrameSinkManager* const host_frame_sink_manager_;
   viz::FrameSinkManagerImpl* const frame_sink_manager_;