Make SingleThreadProxy a SchedulerClient

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/debug/trace_event.h"
 #include "base/logging.h"
@@ skipping 254 matching lines @@
                                       begin_impl_frame_args_.deadline);
   int64 intervals = 1 + ((now - timebase) / begin_impl_frame_args_.interval);
   return timebase + (begin_impl_frame_args_.interval * intervals);
 }
 
 base::TimeTicks Scheduler::LastBeginImplFrameTime() {
   return begin_impl_frame_args_.frame_time;
 }
 
 void Scheduler::SetupNextBeginFrameIfNeeded() {
+  if (!impl_task_runner_)
+    return;
+
   bool needs_begin_frame = state_machine_.BeginFrameNeeded();
 
   if (settings_.throttle_frame_production) {
     SetupNextBeginFrameWhenVSyncThrottlingEnabled(needs_begin_frame);
   } else {
     SetupNextBeginFrameWhenVSyncThrottlingDisabled(needs_begin_frame);
   }
   SetupPollingMechanisms(needs_begin_frame);
 }
 
@@ skipping 205 matching lines @@
 
   begin_retro_frame_posted_ = true;
   impl_task_runner_->PostTask(FROM_HERE, begin_retro_frame_closure_);
 }
 
 // BeginImplFrame starts a compositor frame that will wait up until a deadline
 // for a BeginMainFrame+activation to complete before it times out and draws
 // any asynchronous animation and scroll/pinch updates.
 void Scheduler::BeginImplFrame(const BeginFrameArgs& args) {
   TRACE_EVENT1("cc", "Scheduler::BeginImplFrame", "args", ToTrace(args));
-  DCHECK(state_machine_.begin_impl_frame_state() ==
-         SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE);
+  DCHECK_EQ(state_machine_.begin_impl_frame_state(),
+            SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE);
   DCHECK(state_machine_.HasInitializedOutputSurface());
 
   advance_commit_state_task_.Cancel();
 
   base::TimeDelta draw_duration_estimate = client_->DrawDurationEstimate();
   begin_impl_frame_args_ = args;
   begin_impl_frame_args_.deadline -= draw_duration_estimate;
 
   if (!state_machine_.smoothness_takes_priority() &&
       state_machine_.MainThreadIsInHighLatencyMode() &&
@@ skipping 235 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