Revert of Always use an external begin frame source in the renderer

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 712446fb112f8c8b8274d21ef04335c1f2cd1968..32814bb716a32d57ba8efb2df39280e879305ad8 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -1622,19 +1622,6 @@
 
 std::unique_ptr<cc::BeginFrameSource>
 RenderThreadImpl::CreateExternalBeginFrameSource(int routing_id) {
-  const base::CommandLine* command_line =
-      base::CommandLine::ForCurrentProcess();
-
-  if (command_line->HasSwitch(switches::kUseRemoteCompositing) ||
-      command_line->HasSwitch(switches::kIsRunningInMash) ||
-      command_line->HasSwitch(cc::switches::kDisableBeginFrameScheduling)) {
-    return base::WrapUnique(new cc::DelayBasedBeginFrameSource(
-        base::MakeUnique<cc::DelayBasedTimeSource>(
-            compositor_task_runner_
-                ? compositor_task_runner_.get()
-                : main_thread_compositor_task_runner_.get())));
-  }
-
   return base::WrapUnique(new CompositorExternalBeginFrameSource(
       compositor_message_filter_.get(), sync_message_filter(), routing_id));
 }