cc: Activate when going invisible.

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/debug/trace_event.h"
 #include "base/debug/trace_event_argument.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
@@ skipping 268 matching lines @@
   // activation of the pending tree is blocked by drawing of the active tree and
   // the main thread might be blocked on activation of the most recent commit.
   if (PendingActivationsShouldBeForced())
     return true;
 
   // Additional states where we should abort draws.
   // Note: We don't force activation in these cases because doing so would
   // result in checkerboarding on resize, becoming visible, etc.
   if (!can_draw_)
     return true;
   if (!visible_)

[brianderson, 2014/09/25 18:47:29]

This can be deleted and the comment above should be updated since we don't
actually need to worry about checkerboard anymore with the high res flag and all
that.

[vmpstr, 2014/09/25 19:42:12]

Done.

     return true;
   return false;
 }
 
 bool SchedulerStateMachine::PendingActivationsShouldBeForced() const {
   // These are all the cases where, if we do not force activations to make
   // forward progress, we might deadlock with the main thread.
 
   // There is no output surface to trigger our activations.
   if (output_surface_state_ == OUTPUT_SURFACE_LOST)
     return true;
 
+  // If we're not visible, we should force activation.

[brianderson, 2014/09/25 18:47:29]

Can you explain the whole checkerboarding issue?

Also, the comments in PendingActivationsShouldBeForced and
PendingDrawsShouldBeAborted indicate that they are only used to avoid deadlock,
which will no longer be true.

[vmpstr, 2014/09/25 19:42:12]

Done.

+  if (!visible_)
+    return true;
+
   return false;
 }
 
 bool SchedulerStateMachine::ShouldBeginOutputSurfaceCreation() const {
   // Don't try to initialize too early.
   if (!can_start_)
     return false;
 
   // We only want to start output surface initialization after the
   // previous commit is complete.
@@ skipping 782 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