cc: Make BackToBackBeginFrameSource a SyntheticBeginFrameSource.

cc/scheduler/scheduler_unittest.cc

Index: cc/scheduler/scheduler_unittest.cc
diff --git a/cc/scheduler/scheduler_unittest.cc b/cc/scheduler/scheduler_unittest.cc
index 751c9649e497a230e95fa71102d3197b02f0b5ae..f3bd5ecd0314298ac827a3d9a96d9fbd705a3b41 100644
--- a/cc/scheduler/scheduler_unittest.cc
+++ b/cc/scheduler/scheduler_unittest.cc
@@ -249,8 +249,9 @@ class SchedulerTest : public testing::Test {
         new TestBackToBackBeginFrameSource(now_src_.get(), task_runner_.get()));
     fake_external_begin_frame_source_.reset(
         new FakeExternalBeginFrameSource(client_.get()));
-    synthetic_frame_source_.reset(new TestSyntheticBeginFrameSource(
-        now_src_.get(), task_runner_.get(), BeginFrameArgs::DefaultInterval()));
+    synthetic_frame_source_.reset(new SyntheticBeginFrameSource(
+        base::MakeUnique<TestDelayBasedTimeSource>(now_src_.get(),
+                                                   task_runner_.get())));
     if (!scheduler_settings_.throttle_frame_production) {
       frame_source = unthrottled_frame_source_.get();
     } else if (scheduler_settings_.use_external_begin_frame_source) {
@@ -429,7 +430,7 @@ class SchedulerTest : public testing::Test {
   scoped_refptr<OrderedSimpleTaskRunner> task_runner_;
   std::unique_ptr<FakeExternalBeginFrameSource>
       fake_external_begin_frame_source_;
-  std::unique_ptr<TestSyntheticBeginFrameSource> synthetic_frame_source_;
+  std::unique_ptr<SyntheticBeginFrameSource> synthetic_frame_source_;
   std::unique_ptr<TestBackToBackBeginFrameSource> unthrottled_frame_source_;
   SchedulerSettings scheduler_settings_;
   std::unique_ptr<FakeSchedulerClient> client_;