CC: Add a scheduled action for ManageTiles

cc/scheduler/scheduler_state_machine.cc

Index: cc/scheduler/scheduler_state_machine.cc
diff --git a/cc/scheduler/scheduler_state_machine.cc b/cc/scheduler/scheduler_state_machine.cc
index a608fb902c74864a3203db522e5f72f367a091eb..07a0bee0da2ab8d2b6a66b0e11c0a23a8a967642 100644
--- a/cc/scheduler/scheduler_state_machine.cc
+++ b/cc/scheduler/scheduler_state_machine.cc
@@ -146,6 +146,8 @@ const char* SchedulerStateMachine::ActionToString(Action action) {
       return "ACTION_BEGIN_OUTPUT_SURFACE_CREATION";
     case ACTION_ACQUIRE_LAYER_TEXTURES_FOR_MAIN_THREAD:
       return "ACTION_ACQUIRE_LAYER_TEXTURES_FOR_MAIN_THREAD";
+    case ACTION_MANAGE_TILES:
+      return "ACTION_MANAGE_TILES";
   }
   NOTREACHED();
   return "???";
@@ -209,6 +211,7 @@ scoped_ptr<base::Value> SchedulerStateMachine::AsValue() const  {
   minor_state->SetInteger("consecutive_failed_draws",
                           consecutive_failed_draws_);
   minor_state->SetBoolean("needs_redraw", needs_redraw_);
+  minor_state->SetBoolean("needs_manage_tiles", needs_manage_tiles_);
   minor_state->SetBoolean("swap_used_incomplete_tile",
                           swap_used_incomplete_tile_);
   minor_state->SetBoolean("needs_commit", needs_commit_);
@@ -442,6 +445,10 @@ bool SchedulerStateMachine::ShouldCommit() const {
   return commit_state_ == COMMIT_STATE_READY_TO_COMMIT;
 }
 
+bool SchedulerStateMachine::ShouldManageTiles() const {

[brianderson, 2013/09/11 17:46:27]

Should this function be throttling the calls to ManageTiles at all? Or is
SetNeedsManageTiles properly throttled already. Currently, this will always call
ManageTiles() towards the end of the series of actions within
Scheduler::ProcessScheduledActions.

One way to throttle this to once per frame would be to return false here if we
are not inside a BeginFrame and modify ProactiveBeginFrameWantedByImplThread to
make sure we keep ticking while needs_manage_tiles_ is true.

[epennerAtGoogle, 2013/09/11 18:43:00]

Yes I was concerned about throttling but I didn't know if BeginFrame was the
place to do this. Sounds good.

+  return needs_manage_tiles_;
+}
+
 SchedulerStateMachine::Action SchedulerStateMachine::NextAction() const {
   if (ShouldAcquireLayerTexturesForMainThread())
     return ACTION_ACQUIRE_LAYER_TEXTURES_FOR_MAIN_THREAD;
@@ -461,6 +468,8 @@ SchedulerStateMachine::Action SchedulerStateMachine::NextAction() const {
     else
       return ACTION_DRAW_AND_SWAP_IF_POSSIBLE;
   }
+  if (ShouldManageTiles())
+    return ACTION_MANAGE_TILES;
   if (ShouldSendBeginFrameToMainThread())
     return ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD;
   if (ShouldBeginOutputSurfaceCreation())
@@ -536,6 +545,10 @@ void SchedulerStateMachine::UpdateState(Action action) {
       texture_state_ = LAYER_TEXTURE_STATE_ACQUIRED_BY_MAIN_THREAD;
       main_thread_needs_layer_textures_ = false;
       return;
+
+    case ACTION_MANAGE_TILES:
+      UpdateStateOnManageTiles();
+      return;
   }
 }
 
@@ -677,6 +690,10 @@ void SchedulerStateMachine::UpdateStateOnDraw(bool did_swap) {
     last_frame_number_swap_performed_ = current_frame_number_;
 }
 
+void SchedulerStateMachine::UpdateStateOnManageTiles() {
+  needs_manage_tiles_ = false;
+}
+
 void SchedulerStateMachine::SetMainThreadNeedsLayerTextures() {
   DCHECK(!main_thread_needs_layer_textures_);
   DCHECK_NE(texture_state_, LAYER_TEXTURE_STATE_ACQUIRED_BY_MAIN_THREAD);
@@ -757,6 +774,10 @@ void SchedulerStateMachine::SetVisible(bool visible) { visible_ = visible; }
 
 void SchedulerStateMachine::SetNeedsRedraw() { needs_redraw_ = true; }
 
+void SchedulerStateMachine::SetNeedsManageTiles() {
+  needs_manage_tiles_ = true;
+}
+
 void SchedulerStateMachine::SetSwapUsedIncompleteTile(
     bool used_incomplete_tile) {
   swap_used_incomplete_tile_ = used_incomplete_tile;