Revert of Plumb activation time to main

cc/trees/proxy_main.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/proxy_main.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/memory/ptr_util.h"
@@ skipping 100 matching lines @@
   DCHECK(IsMainThread());
   layer_tree_host_->DidCompletePageScaleAnimation();
 }
 
 void ProxyMain::BeginMainFrame(
     std::unique_ptr<BeginMainFrameAndCommitState> begin_main_frame_state) {
   benchmark_instrumentation::ScopedBeginFrameTask begin_frame_task(
       benchmark_instrumentation::kDoBeginFrame,
       begin_main_frame_state->begin_frame_id);
 
-  begin_main_frame_state->begin_frame_args.source_frame_number =
-      layer_tree_host_->SourceFrameNumber();
-
   base::TimeTicks begin_main_frame_start_time = base::TimeTicks::Now();
 
   TRACE_EVENT_SYNTHETIC_DELAY_BEGIN("cc.BeginMainFrame");
   DCHECK(IsMainThread());
   DCHECK_EQ(NO_PIPELINE_STAGE, current_pipeline_stage_);
 
   // We need to issue image decode callbacks whether or not we will abort this
   // commit, since the callbacks are only stored in |begin_main_frame_state|.
   for (auto& callback :
        begin_main_frame_state->completed_image_decode_callbacks) {
@@ skipping 388 matching lines @@
 
 bool ProxyMain::IsImplThread() const {
   return task_runner_provider_->IsImplThread();
 }
 
 base::SingleThreadTaskRunner* ProxyMain::ImplThreadTaskRunner() {
   return task_runner_provider_->ImplThreadTaskRunner();
 }
 
 }  // namespace cc