cc: Remove background ticking from LTHI.

cc/scheduler/scheduler_state_machine.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_state_machine.h"
 
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 659 matching lines @@
 
   return false;
 }
 
 bool SchedulerStateMachine::BeginFrameNeeded() const {
   // We can't handle BeginFrames when output surface isn't initialized.
   // TODO(brianderson): Support output surface creation inside a BeginFrame.
   if (!HasInitializedOutputSurface())
     return false;
 
+  // If we are not visible, we don't need BeginFrame messages.
+  if (!visible_) {

[brianderson, 2015/04/01 21:58:08]

Can you remove the visibility checks in BeginFrameNeededToAnimateOrDraw and
ProactiveBeginFrameWanted?

If the Renderers are requesting BeginFrames, we should probably give it to them
and move BeginFrameNeededForChildren() to before the !visible check. Otherwise,
DCHECK_IMPLIES(!visible, !BeginFrameNeededForChildren)?

[mithro-old, 2015/04/02 01:03:59]

I moved the !visible_ check into the BeginFrameNeededToAnimateOrDraw method
which I think fixes your concerns?

+    return false;
+  }
+
   if (SupportsProactiveBeginFrame()) {
     return (BeginFrameNeededToAnimateOrDraw() ||
             BeginFrameNeededForChildren() ||
             ProactiveBeginFrameWanted());
   }
 
   // Proactive BeginFrames are bad for the synchronous compositor because we
   // have to draw when we get the BeginFrame and could end up drawing many
   // duplicate frames if our new frame isn't ready in time.
   // To poll for state with the synchronous compositor without having to draw,
@@ skipping 130 matching lines @@
   }
 }
 
 bool SchedulerStateMachine::ShouldTriggerBeginImplFrameDeadlineImmediately()
     const {
   // TODO(brianderson): This should take into account multiple commit sources.
 
   if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME)
     return false;
 
-  // If we've lost the output surface, end the current BeginImplFrame ASAP
-  // so we can start creating the next output surface.
-  if (output_surface_state_ == OUTPUT_SURFACE_LOST)
+  // If things are being aborted, end the current BeginImplFrame ASAP so we can
+  // unblock creating the next output surface.
+  if (PendingDrawsShouldBeAborted())

[brianderson, 2015/04/01 21:58:08]

This seems unrelated. Make this a separate patch?

[mithro-old, 2015/04/02 01:03:59]

Done.

     return true;
 
   // SwapAck throttle the deadline since we wont draw and swap anyway.
   if (pending_swaps_ >= max_pending_swaps_)
     return false;
 
   if (active_tree_needs_first_draw_)
     return true;
 
   if (!needs_redraw_)
@@ skipping 237 matching lines @@
       static_cast<int>(begin_impl_frame_state_),
       static_cast<int>(commit_state_),
       has_pending_tree_ ? 'T' : 'F',
       pending_tree_is_ready_for_activation_ ? 'T' : 'F',
       active_tree_needs_first_draw_ ? 'T' : 'F',
       max_pending_swaps_,
       pending_swaps_);
 }
 
 }  // namespace cc