[cc] Test that CFSSupport forwards BeginFrameAcks in CompositorFrames.

cc/surfaces/compositor_frame_sink_support_unittest.cc

 // Copyright 2017 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/compositor_frame_sink_support.h"
 
 #include "base/debug/stack_trace.h"
 #include "base/macros.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/surfaces/compositor_frame_sink_support_client.h"
@@ skipping 940 matching lines @@
   aggregated_latency_info.AddNewLatencyFrom(info_list[1]);
   EXPECT_EQ(2u, aggregated_latency_info.latency_components().size());
 
   ui::LatencyInfo::LatencyComponent comp1;
   EXPECT_TRUE(
       aggregated_latency_info.FindLatency(latency_type1, latency_id1, &comp1));
   EXPECT_EQ(latency_sequence_number1, comp1.sequence_number);
 }
 
 TEST_F(CompositorFrameSinkSupportTest, PassesOnBeginFrameAcks) {
+  const SurfaceId display_id = MakeSurfaceId(kDisplayFrameSink, 1);
+
   // Request BeginFrames.
   display_support().SetNeedsBeginFrame(true);
 
   // Issue a BeginFrame.
   BeginFrameArgs args =
       CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, 0, 1);
   begin_frame_source()->TestOnBeginFrame(args);
 
   // Check that the support forwards a BeginFrameDidNotSwap ack to the
   // BeginFrameSource.
   BeginFrameAck ack(0, 1, 1, false);
   display_support().BeginFrameDidNotSwap(ack);
   EXPECT_EQ(ack, begin_frame_source()->LastAckForObserver(&display_support()));
 
-  // TODO(eseckler): Check that the support forwards the BeginFrameAck attached
+  // Issue another BeginFrame.
+  args = CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, 0, 2);
+  begin_frame_source()->TestOnBeginFrame(args);
+
+  // Check that the support forwards the BeginFrameAck attached
   // to a CompositorFrame to the BeginFrameSource.
+  BeginFrameAck ack2(0, 2, 2, true);
+  CompositorFrame frame = MakeCompositorFrame();
+  frame.metadata.begin_frame_ack = ack2;
+  display_support().SubmitCompositorFrame(display_id.local_surface_id(),
+                                          std::move(frame));
+  EXPECT_EQ(ack2, begin_frame_source()->LastAckForObserver(&display_support()));
 }
 
 // Checks whether the resources are returned before we send an ack.
 TEST_F(CompositorFrameSinkSupportTest, ReturnResourcesBeforeAck) {
   const SurfaceId parent_id = MakeSurfaceId(kParentFrameSink, 1);
   TransferableResource resource;
   resource.id = 1234;
   parent_support().SubmitCompositorFrame(
       parent_id.local_surface_id(),
       MakeCompositorFrameWithResources(empty_surface_ids(), {resource}));
@@ skipping 108 matching lines @@
   // be used and destroyed() must return false. The surface must have a factory.
   child_support->SubmitCompositorFrame(
       child_id.local_surface_id(), MakeCompositorFrame(empty_surface_ids()));
   EXPECT_EQ(surface, surface_manager().GetSurfaceForId(child_id));
   EXPECT_TRUE(surface->factory());
   EXPECT_FALSE(surface->destroyed());
 }
 
 }  // namespace test
 }  // namespace cc