Remove uses of external begin frame sources

content/test/fake_compositor_dependencies.cc

Index: content/test/fake_compositor_dependencies.cc
diff --git a/content/test/fake_compositor_dependencies.cc b/content/test/fake_compositor_dependencies.cc
index 15de2d9fdcffafa501675b6c92420f60e3f5d6e6..79bbe57b1c32532a1ead17f2de9e57e2d4b015ed 100644
--- a/content/test/fake_compositor_dependencies.cc
+++ b/content/test/fake_compositor_dependencies.cc
@@ -90,14 +90,6 @@ FakeCompositorDependencies::GetRendererScheduler() {
   return &renderer_scheduler_;
 }
 
-std::unique_ptr<cc::BeginFrameSource>
-FakeCompositorDependencies::CreateExternalBeginFrameSource(int routing_id) {
-  double refresh_rate = 200.0;
-  bool tick_automatically = true;
-  return base::MakeUnique<cc::FakeExternalBeginFrameSource>(refresh_rate,
-                                                            tick_automatically);
-}
-
 cc::ImageSerializationProcessor*
 FakeCompositorDependencies::GetImageSerializationProcessor() {
   return nullptr;