Make disable vsync run the renderer independently

cc/surfaces/surface_manager_unittest.cc

Index: cc/surfaces/surface_manager_unittest.cc
diff --git a/cc/surfaces/surface_manager_unittest.cc b/cc/surfaces/surface_manager_unittest.cc
index 9c290944d30b49ae7fe07f9371577dce6db4d91d..301ff49354d8614d270d6aca28ae99d5f8c72c8b 100644
--- a/cc/surfaces/surface_manager_unittest.cc
+++ b/cc/surfaces/surface_manager_unittest.cc
@@ -56,14 +56,6 @@ class FakeSurfaceFactoryClient : public SurfaceFactoryClient {
   uint32_t id_namespace_;
 };
 
-class EmptyBeginFrameSource : public BeginFrameSource {
- public:
-  void DidFinishFrame(BeginFrameObserver* obs,
-                      size_t remaining_frames) override {}
-  void AddObserver(BeginFrameObserver* obs) override {}
-  void RemoveObserver(BeginFrameObserver* obs) override {}
-};
-
 class SurfaceManagerTest : public testing::Test {
  public:
   // These tests don't care about namespace registration, so just preregister
@@ -88,7 +80,7 @@ class SurfaceManagerTest : public testing::Test {
 TEST_F(SurfaceManagerTest, SingleClients) {
   FakeSurfaceFactoryClient client(1);
   FakeSurfaceFactoryClient other_client(2);
-  EmptyBeginFrameSource source;
+  StubBeginFrameSource source;
 
   EXPECT_EQ(client.source(), nullptr);
   EXPECT_EQ(other_client.source(), nullptr);
@@ -121,8 +113,8 @@ TEST_F(SurfaceManagerTest, SingleClients) {
 }
 
 TEST_F(SurfaceManagerTest, MultipleDisplays) {
-  EmptyBeginFrameSource root1_source;
-  EmptyBeginFrameSource root2_source;
+  StubBeginFrameSource root1_source;
+  StubBeginFrameSource root2_source;
 
   // root1 -> A -> B
   // root2 -> C
@@ -291,7 +283,7 @@ class SurfaceManagerOrderingTest : public SurfaceManagerTest {
     AssertAllValidBFS();
   }
 
-  EmptyBeginFrameSource source_;
+  StubBeginFrameSource source_;
   // A -> B -> C hierarchy, with A always having the BFS.
   FakeSurfaceFactoryClient client_a_;
   FakeSurfaceFactoryClient client_b_;