cc: Disable Renderer latency recovery with --disable-gpu-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 750 matching lines @@
   // main thread in a high latency mode. Don't try to fight it.
   if (state_machine_.impl_latency_takes_priority())
     return false;
 
   return CanCommitAndActivateBeforeDeadline(args);
 }
 
 bool Scheduler::ShouldRecoverImplLatency(const BeginFrameArgs& args) const {
   DCHECK(!settings_.using_synchronous_renderer_compositor);
 
+  // Disable impl thread latency recovery when using the unthrottled
+  // begin frame source since we will always get a BeginFrame before
+  // the swap ack and our heuristics below will not work.
+  if (!throttle_frame_production_)
+    return false;
+
   // If we are swap throttled at the BeginFrame, that means the impl thread is
   // very likely in a high latency mode.
   bool impl_thread_is_likely_high_latency = state_machine_.SwapThrottled();
   if (!impl_thread_is_likely_high_latency)
     return false;
 
   // The deadline may be in the past if our draw time is too long.
   bool can_draw_before_deadline = args.frame_time < args.deadline;
 
   // When prioritizing impl thread latency, the deadline doesn't wait
@@ skipping 27 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