Add a bunch of vlogs to RAF related calls in chrome.

cc/trees/thread_proxy.cc

Index: cc/trees/thread_proxy.cc
diff --git a/cc/trees/thread_proxy.cc b/cc/trees/thread_proxy.cc
index 4a95140226db8fd2c72da44e632ebdd880bf1f5e..688937eda3a8f15fc3e0daf9c8452d84926f0bbe 100644
--- a/cc/trees/thread_proxy.cc
+++ b/cc/trees/thread_proxy.cc
@@ -677,6 +677,7 @@ void ThreadProxy::FinishAllRenderingOnImplThread(CompletionEvent* completion) {
 }
 
 void ThreadProxy::ScheduledActionSendBeginMainFrame() {
+  VLOG(2) << "ThreadProxy::ScheduledActionSendBeginMainFrame";
   unsigned int begin_frame_id = nextBeginFrameId++;
   benchmark_instrumentation::ScopedBeginFrameTask begin_frame_task(
       benchmark_instrumentation::kSendBeginFrame, begin_frame_id);
@@ -715,11 +716,14 @@ void ThreadProxy::BeginMainFrame(
   TRACE_EVENT_SYNTHETIC_DELAY_BEGIN("cc.BeginMainFrame");
   DCHECK(IsMainThread());
 
+  VLOG(2) << "ThreadProxy::BeginMainFrame - BEGIN";
+
   if (main().defer_commits) {
     main().pending_deferred_commit = begin_main_frame_state.Pass();
     layer_tree_host()->DidDeferCommit();
     TRACE_EVENT_INSTANT0(
         "cc", "EarlyOut_DeferCommits", TRACE_EVENT_SCOPE_THREAD);
+    VLOG(2) << "ThreadProxy::BeginMainFrame: EarlyOut_DeferCommits";
     return;
   }
 
@@ -734,6 +738,7 @@ void ThreadProxy::BeginMainFrame(
 
   if (!layer_tree_host()->visible()) {
     TRACE_EVENT_INSTANT0("cc", "EarlyOut_NotVisible", TRACE_EVENT_SCOPE_THREAD);
+    VLOG(2) << "ThreadProxy::BeginMainFrame: EarlyOut_NotVisible";
     bool did_handle = false;
     Proxy::ImplThreadTaskRunner()->PostTask(
         FROM_HERE,
@@ -746,6 +751,7 @@ void ThreadProxy::BeginMainFrame(
   if (layer_tree_host()->output_surface_lost()) {
     TRACE_EVENT_INSTANT0(
         "cc", "EarlyOut_OutputSurfaceLost", TRACE_EVENT_SCOPE_THREAD);
+    VLOG(2) << "ThreadProxy::BeginMainFrame: EarlyOut_OutputSurfaceLost";
     bool did_handle = false;
     Proxy::ImplThreadTaskRunner()->PostTask(
         FROM_HERE,
@@ -825,6 +831,7 @@ void ThreadProxy::BeginMainFrame(
 
   if (!updated && can_cancel_this_commit) {
     TRACE_EVENT_INSTANT0("cc", "EarlyOut_NoUpdates", TRACE_EVENT_SCOPE_THREAD);
+    VLOG(2) << "ThreadProxy::BeginMainFrame: EarlyOut_NoUpdates";
     bool did_handle = true;
     Proxy::ImplThreadTaskRunner()->PostTask(
         FROM_HERE,