Create a new action triggered when a BeginMainFrame is not expected before vsync

cc/scheduler/scheduler.cc

 // Copyright 2011 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/scheduler/scheduler.h"
 
 #include <algorithm>
 
 #include "base/auto_reset.h"
 #include "base/logging.h"
@@ skipping 197 matching lines @@
     base::TimeTicks main_thread_start_time) {
   TRACE_EVENT0("cc", "Scheduler::NotifyBeginMainFrameStarted");
   state_machine_.NotifyBeginMainFrameStarted();
   compositor_timing_history_->BeginMainFrameStarted(main_thread_start_time);
 }
 
 base::TimeTicks Scheduler::LastBeginImplFrameTime() {
   return begin_impl_frame_tracker_.Current().frame_time;
 }
 
+void Scheduler::BeginMainFrameNotExpectedUntil(base::TimeTicks time) {
+  TRACE_EVENT0("cc", "Scheduler::BeginMainFrameNotExpectedUntil");
+  compositor_timing_history_->BeginImplFrameNotExpectedSoon();

[brianderson, 2017/04/07 22:03:16]

Do not call compositor_timing_history_->BeingImplFrameNoExpectedSoon here since
that's used a signal that we've gone idle; but we haven't necessarily gone idle
at this point.

[Dan Elphick, 2017/04/10 15:53:22]

Done.

+  client_->ScheduledActionBeginMainFrameNotExpectedUntil(time);
+}
+
 void Scheduler::BeginImplFrameNotExpectedSoon() {
   compositor_timing_history_->BeginImplFrameNotExpectedSoon();
 
   // Tying this to SendBeginMainFrameNotExpectedSoon will have some
   // false negatives, but we want to avoid running long idle tasks when
   // we are actually active.
   client_->SendBeginMainFrameNotExpectedSoon();
 }
 
 void Scheduler::SetupNextBeginFrameIfNeeded() {
@@ skipping 394 matching lines @@
       case SchedulerStateMachine::ACTION_NONE:
         break;
       case SchedulerStateMachine::ACTION_SEND_BEGIN_MAIN_FRAME:
         compositor_timing_history_->WillBeginMainFrame(
             begin_main_frame_args_.on_critical_path,
             begin_main_frame_args_.frame_time);
         state_machine_.WillSendBeginMainFrame();
         // TODO(brianderson): Pass begin_main_frame_args_ directly to client.
         client_->ScheduledActionSendBeginMainFrame(begin_main_frame_args_);
         break;
+      case SchedulerStateMachine::ACTION_NOTIFY_BEGIN_MAIN_FRAME_NOT_SENT:
+        state_machine_.WillNotifyBeginMainFrameNotSent();
+        BeginMainFrameNotExpectedUntil(begin_main_frame_args_.frame_time +
+                                       begin_main_frame_args_.interval);
+        break;
       case SchedulerStateMachine::ACTION_COMMIT: {
         bool commit_has_no_updates = false;
         state_machine_.WillCommit(commit_has_no_updates);
         client_->ScheduledActionCommit();
         break;
       }
       case SchedulerStateMachine::ACTION_ACTIVATE_SYNC_TREE:
         compositor_timing_history_->WillActivate();
         state_machine_.WillActivate();
         client_->ScheduledActionActivateSyncTree();
@@ skipping 157 matching lines @@
 }
 
 BeginFrameAck Scheduler::CurrentBeginFrameAckForActiveTree() const {
   return BeginFrameAck(
       begin_main_frame_args_.source_id, begin_main_frame_args_.sequence_number,
       state_machine_.last_begin_frame_sequence_number_active_tree_was_fresh(),
       true);
 }
 
 }  // namespace cc