Revert of Plumb activation time to main

cc/scheduler/begin_frame_source.cc

Index: cc/scheduler/begin_frame_source.cc
diff --git a/cc/scheduler/begin_frame_source.cc b/cc/scheduler/begin_frame_source.cc
index ebd9d5071db3d69d57541ba8bcab7aa6aaabca4a..36e3a62aa055b57b6ba52d9ef6576e4d6824d3ba 100644
--- a/cc/scheduler/begin_frame_source.cc
+++ b/cc/scheduler/begin_frame_source.cc
@@ -129,8 +129,7 @@
   base::TimeTicks frame_time = time_source_->LastTickTime();
   base::TimeDelta default_interval = BeginFrameArgs::DefaultInterval();
   BeginFrameArgs args = BeginFrameArgs::Create(
-      BEGINFRAME_FROM_HERE, source_id(), next_sequence_number_,
-      BeginFrameArgs::kDefaultSourceFrameNumber, frame_time,
+      BEGINFRAME_FROM_HERE, source_id(), next_sequence_number_, frame_time,
       frame_time + default_interval, default_interval, BeginFrameArgs::NORMAL);
   next_sequence_number_++;
 
@@ -179,8 +178,7 @@
     BeginFrameArgs::BeginFrameArgsType type) {
   uint64_t sequence_number = next_sequence_number_++;
   return BeginFrameArgs::Create(
-      BEGINFRAME_FROM_HERE, source_id(), sequence_number,
-      BeginFrameArgs::kDefaultSourceFrameNumber, frame_time,
+      BEGINFRAME_FROM_HERE, source_id(), sequence_number, frame_time,
       time_source_->NextTickTime(), time_source_->Interval(), type);
 }