Plumb activation time to main

third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc

Index: third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc
index fe476ff8ad6e49f284c865eed04c4ecc92a8b6fd..d246363360af140f0b2ceb4432dc6545499611a6 100644
--- a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc
+++ b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc
@@ -405,6 +405,11 @@ void RendererSchedulerImpl::WillBeginFrame(const cc::BeginFrameArgs& args) {
   if (helper_.IsShutdown())
     return;
 
+  fprintf(stderr,
+          "\nRendererSchedulerImpl::WillBeginFrame: current frame: %d, "
+          "activated frame: %d",
+          args.frame_source_number, args.ready_to_activate_source_frame_number);
+
   EndIdlePeriod();
   MainThreadOnly().estimated_next_frame_begin = args.frame_time + args.interval;
   MainThreadOnly().have_seen_a_begin_main_frame = true;