[cc] Forward BeginFrameAcks through DirectCFS and CFSSupport.

cc/surfaces/direct_compositor_frame_sink_unittest.cc

Index: cc/surfaces/direct_compositor_frame_sink_unittest.cc
diff --git a/cc/surfaces/direct_compositor_frame_sink_unittest.cc b/cc/surfaces/direct_compositor_frame_sink_unittest.cc
index 8ce6043c937f0c9bd3555898c8fbfa09c6f2603e..3bc52f1621a94e17fc062330e0baf5cf091090fe 100644
--- a/cc/surfaces/direct_compositor_frame_sink_unittest.cc
+++ b/cc/surfaces/direct_compositor_frame_sink_unittest.cc
@@ -16,6 +16,7 @@
 #include "cc/surfaces/frame_sink_id.h"
 #include "cc/surfaces/local_surface_id_allocator.h"
 #include "cc/surfaces/surface_manager.h"
+#include "cc/test/begin_frame_args_test.h"
 #include "cc/test/fake_compositor_frame_sink_client.h"
 #include "cc/test/fake_output_surface.h"
 #include "cc/test/ordered_simple_task_runner.h"
@@ -29,6 +30,35 @@ namespace {
 
 static constexpr FrameSinkId kArbitraryFrameSinkId(1, 1);
 
+class ObserverTrackingBeginFrameSource : public BackToBackBeginFrameSource {
+ public:
+  using BackToBackBeginFrameSource::BackToBackBeginFrameSource;
+
+  void DidFinishFrame(BeginFrameObserver* obs,
+                      const BeginFrameAck& ack) override {
+    BackToBackBeginFrameSource::DidFinishFrame(obs, ack);
+    if (obs == tracked_observer_)
+      last_ack_ = ack;
+  }
+
+  void set_tracked_observer(BeginFrameObserver* obs) {
+    tracked_observer_ = obs;
+  }
+
+  const BeginFrameAck& last_ack() const { return last_ack_; }
+
+ private:
+  BeginFrameObserver* tracked_observer_ = nullptr;
+  BeginFrameAck last_ack_;
+};
+
+class TestDirectCompositorFrameSink : public DirectCompositorFrameSink {
+ public:
+  using DirectCompositorFrameSink::DirectCompositorFrameSink;
+
+  CompositorFrameSinkSupport* support() const { return support_.get(); }
+};
+
 class DirectCompositorFrameSinkTest : public testing::Test {
  public:
   DirectCompositorFrameSinkTest()
@@ -43,7 +73,7 @@ class DirectCompositorFrameSinkTest : public testing::Test {
         FakeOutputSurface::Create3d();
     display_output_surface_ = display_output_surface.get();
 
-    begin_frame_source_.reset(new BackToBackBeginFrameSource(
+    begin_frame_source_.reset(new ObserverTrackingBeginFrameSource(
         base::MakeUnique<DelayBasedTimeSource>(task_runner_.get())));
 
     int max_frames_pending = 2;
@@ -55,12 +85,14 @@ class DirectCompositorFrameSinkTest : public testing::Test {
         kArbitraryFrameSinkId, begin_frame_source_.get(),
         std::move(display_output_surface), std::move(scheduler),
         base::MakeUnique<TextureMailboxDeleter>(task_runner_.get())));
-    compositor_frame_sink_.reset(new DirectCompositorFrameSink(
+    compositor_frame_sink_.reset(new TestDirectCompositorFrameSink(
         kArbitraryFrameSinkId, &surface_manager_, display_.get(),
         context_provider_, nullptr, &gpu_memory_buffer_manager_,
         &bitmap_manager_));
 
     compositor_frame_sink_->BindToClient(&compositor_frame_sink_client_);
+    begin_frame_source_->set_tracked_observer(
+        compositor_frame_sink_->support());
     display_->Resize(display_size_);
     display_->SetVisible(true);
 
@@ -103,10 +135,10 @@ class DirectCompositorFrameSinkTest : public testing::Test {
 
   scoped_refptr<TestContextProvider> context_provider_;
   FakeOutputSurface* display_output_surface_ = nullptr;
-  std::unique_ptr<BeginFrameSource> begin_frame_source_;
+  std::unique_ptr<ObserverTrackingBeginFrameSource> begin_frame_source_;
   std::unique_ptr<Display> display_;
   FakeCompositorFrameSinkClient compositor_frame_sink_client_;
-  std::unique_ptr<DirectCompositorFrameSink> compositor_frame_sink_;
+  std::unique_ptr<TestDirectCompositorFrameSink> compositor_frame_sink_;
 };
 
 TEST_F(DirectCompositorFrameSinkTest, DamageTriggersSwapBuffers) {
@@ -151,5 +183,37 @@ TEST_F(DirectCompositorFrameSinkTest,
   EXPECT_EQ(1u, display_output_surface_->num_sent_frames());
 }
 
+class TestBeginFrameObserver : public BeginFrameObserverBase {
+ public:
+  explicit TestBeginFrameObserver(BeginFrameSource* source) : source_(source) {}
+
+  void FinishFrame() { source_->DidFinishFrame(this, ack()); }
+
+  const BeginFrameAck& ack() const { return ack_; }
+
+ private:
+  bool OnBeginFrameDerivedImpl(const BeginFrameArgs& args) override {
+    ack_ = BeginFrameAck(args.source_id, args.sequence_number,
+                         args.sequence_number, 0, true);
+    return true;
+  }
+
+  void OnBeginFrameSourcePausedChanged(bool paused) override{};
+
+  BeginFrameSource* source_;
+  BeginFrameAck ack_;
+};
+
+TEST_F(DirectCompositorFrameSinkTest, AcknowledgesBeginFrames) {
+  // Request a BeginFrame from the CompositorFrameSinkClient.
+  TestBeginFrameObserver observer(begin_frame_source_.get());
+  compositor_frame_sink_client_.begin_frame_source()->AddObserver(&observer);
+  observer.FinishFrame();
+  compositor_frame_sink_client_.begin_frame_source()->RemoveObserver(&observer);
+
+  // Verify that the frame sink acknowledged the last BeginFrame.
+  EXPECT_EQ(observer.ack(), begin_frame_source_->last_ack());
+}
+
 }  // namespace
 }  // namespace cc