Plumb activation time to main

cc/scheduler/scheduler.cc

Index: cc/scheduler/scheduler.cc
diff --git a/cc/scheduler/scheduler.cc b/cc/scheduler/scheduler.cc
index d532ce3b07d7478d7eea238f0df43884f7d299e5..de4dada566e86ddcafb844f335594ef45d6c44c5 100644
--- a/cc/scheduler/scheduler.cc
+++ b/cc/scheduler/scheduler.cc
@@ -89,9 +89,17 @@ void Scheduler::SetCanDraw(bool can_draw) {
   ProcessScheduledActions();
 }
 
-void Scheduler::NotifyReadyToActivate() {
+void Scheduler::NotifyReadyToActivate(int sync_tree) {
   compositor_timing_history_->ReadyToActivate();
   state_machine_.NotifyReadyToActivate();
+  // Note the activate source-frame and timestamp
+  if (sync_tree != 0) {
+    ready_to_activate_time_.emplace_back(
+        std::make_pair(sync_tree, base::TimeTicks::Now()));

[brianderson, 2017/04/10 23:12:47]

I was under the impression you might be able to remove the std::make_pair here
with emplace_back. Is that possible?

[panicker, 2017/04/11 22:19:37]

Good catch, done.

+    /* TODO: REMOVE ME */
+    fprintf(stderr, "\n\t\tScheduler::NotifyReadyToActivate: synctree: %d",
+            sync_tree);
+  }
   ProcessScheduledActions();
 }
 
@@ -627,6 +635,8 @@ void Scheduler::ProcessScheduledActions() {
             begin_main_frame_args_.frame_time);
         state_machine_.WillSendBeginMainFrame();
         // TODO(brianderson): Pass begin_main_frame_args_ directly to client.
+        begin_main_frame_args_.ready_to_activate_time =
+            std::move(ready_to_activate_time_);

[brianderson, 2017/04/10 23:12:47]

After the move, ready_to_activate_time_ is in an valid but unspecified state.
clear() should be called on it so it's in a valid and specified state.

[panicker, 2017/04/11 22:19:37]

Done.

         client_->ScheduledActionSendBeginMainFrame(begin_main_frame_args_);
         break;
       case SchedulerStateMachine::ACTION_COMMIT: {