cc: Aggressively expire retro frames.

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 416 matching lines @@
   // Today, we should always end up with at most one un-expired BeginRetroFrame
   // because deadlines will not be greater than the next frame time. We don't
   // DCHECK though because some systems don't always have monotonic timestamps.
   // TODO(brianderson): In the future, long deadlines could result in us not
   // draining the queue if we don't catch up. If we consistently can't catch
   // up, our fallback should be to lower our frame rate.
   base::TimeTicks now = Now();
 
   while (!begin_retro_frame_args_.empty()) {
     const BeginFrameArgs& args = begin_retro_frame_args_.front();
-    base::TimeTicks expiration_time = args.frame_time + args.interval;
+    base::TimeTicks expiration_time = args.deadline;
     if (now <= expiration_time)
       break;
     TRACE_EVENT_INSTANT2(
         "cc", "Scheduler::BeginRetroFrame discarding", TRACE_EVENT_SCOPE_THREAD,
         "expiration_time - now", (expiration_time - now).InMillisecondsF(),
         "BeginFrameArgs", begin_retro_frame_args_.front().AsValue());
     begin_retro_frame_args_.pop_front();
     frame_source_->DidFinishFrame(begin_retro_frame_args_.size());
   }
 
@@ skipping 375 matching lines @@
 }
 
 bool Scheduler::IsBeginMainFrameSentOrStarted() const {
   return (state_machine_.commit_state() ==
               SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT ||
           state_machine_.commit_state() ==
               SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED);
 }
 
 }  // namespace cc