Add BeginFrameObserverProxy

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 362 matching lines @@
 }
 
 // BeginFrame is the mechanism that tells us that now is a good time to start
 // making a frame. Usually this means that user input for the frame is complete.
 // If the scheduler is busy, we queue the BeginFrame to be handled later as
 // a BeginRetroFrame.
 bool Scheduler::OnBeginFrameMixInDelegate(const BeginFrameArgs& args) {
   TRACE_EVENT1("cc,benchmark", "Scheduler::BeginFrame", "args", args.AsValue());
 
   // Deliver BeginFrames to children.
-  if (settings_.forward_begin_frames_to_children &&
-      state_machine_.children_need_begin_frames()) {
+  if (state_machine_.children_need_begin_frames()) {

[danakj, 2015/03/13 17:57:11]

If this patch isn't enabling stuff, but it's already removing code, then these
removals seem independent and like something you could do in an even smaller CL?

[simonhong, 2015/03/17 16:11:34]

Yep, this is removed in a separate cl.

     BeginFrameArgs adjusted_args_for_children(args);
     // Adjust a deadline for child schedulers.
     // TODO(simonhong): Once we have commitless update, we can get rid of
     // BeginMainFrameToCommitDurationEstimate() +
     // CommitToActivateDurationEstimate().
     adjusted_args_for_children.deadline -=
         (client_->BeginMainFrameToCommitDurationEstimate() +
          client_->CommitToActivateDurationEstimate() +
          client_->DrawDurationEstimate() + EstimatedParentDrawTime());
     client_->SendBeginFramesToChildren(adjusted_args_for_children);
@@ skipping 29 matching lines @@
     TRACE_EVENT_INSTANT0(
         "cc", "Scheduler::BeginFrame deferred", TRACE_EVENT_SCOPE_THREAD);
     // Queuing the frame counts as "using it", so we need to return true.
   } else {
     BeginImplFrame(adjusted_args);
   }
   return true;
 }
 
 void Scheduler::SetChildrenNeedBeginFrames(bool children_need_begin_frames) {
-  DCHECK(settings_.forward_begin_frames_to_children);
   state_machine_.SetChildrenNeedBeginFrames(children_need_begin_frames);
   ProcessScheduledActions();
 }
 
 // BeginRetroFrame is called for BeginFrames that we've deferred because
 // the scheduler was in the middle of processing a previous BeginFrame.
 void Scheduler::BeginRetroFrame() {
   TRACE_EVENT0("cc,benchmark", "Scheduler::BeginRetroFrame");
   DCHECK(!settings_.using_synchronous_renderer_compositor);
   DCHECK(!begin_retro_frame_args_.empty());
@@ skipping 425 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