CC: Add a scheduled action for ManageTiles

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 5546ea33d36ce5773120089d2538164aaec607e9..a2fc09b9a9c69bbff5f0624f609382b047e5586c 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -2468,6 +2468,13 @@ void LayerTreeHostImpl::SetTreePriority(TreePriority priority) {
   new_state.tree_priority = priority;
   tile_manager_->SetGlobalState(new_state);
   manage_tiles_needed_ = true;
+
+  // We may have blocked activation entirely while in smoothness
+  // mode due to not prioritizing pending tree tiles. When transitioning
+  // out of smoothness mode, this is here to insure we do call manage-tiles
+  // again (to insure reprioritize and activate).
+  if (priority != SMOOTHNESS_TAKES_PRIORITY)

[reveman, 2013/09/03 19:03:21]

We need this to trigger a call to ManageTiles() even without this change. It's a
bug if that is not already happening. Not sure
client_->SetNeedsRedrawOnImplThread() is the best way to enforce this. Maybe the
best is to just call ManageTiles() here directly. Brian, Enne, any suggestions?

+    client_->SetNeedsRedrawOnImplThread();

[enne (OOO), 2013/09/03 19:11:13]

Sorry, but I don't follow this.  If we're missing a call to ManageTiles without
a redraw then that seems like a larger issue that should be solved outside this
patch.

[epenner, 2013/09/03 19:27:53]

The current problem case is a double-tap zoom animation. In that case we don't
activate after the zoom is finished, unless we do another accelerated scroll.

If this is a deeper bug, I'll remove this code from this patch and work on a
better fix for that in a separate patch.

 }
 
 void LayerTreeHostImpl::ResetCurrentFrameTimeForNextFrame() {