Allows fullscreen to be triggered with the key events used for scrolling.

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index 7b0972645a5a0157c49564324626a6dd5b7dfbbd..50d58e8a68b6b1d2a729ea1d5a2acccb33931798 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -492,6 +492,18 @@ scoped_ptr<LayerTreeHostImpl> LayerTreeHost::CreateLayerTreeHostImpl(
   return host_impl.Pass();
 }
 
+void LayerTreeHost::ShowTopControls(bool show) {
+  top_controls_manager_weak_ptr_->ScrollBegin();

[aelias_OOO_until_Jul13, 2013/05/21 05:51:41]

This isn't thread-safe.  LayerTreeHost functions are called on the main thread
but the top controls manager is owned on the impl thread.  

I recommend waiting until https://codereview.chromium.org/14139013/ lands and
making use of LayerTreeHost::UpdateTopControlsState() instead.  You may need to
keep an additional copy of the latest constraints state on the main thread.

[Jinsuk Kim, 2013/05/24 09:57:13]

Done. Instead of keeping an additional copy I added an overloaded method of
UpdateTopControlsState that preserves the constraints. Please see if it looks
fine.

+  gfx::Vector2dF delta(0.f, show ? -settings_.top_controls_height
+                                  : settings_.top_controls_height);
+  top_controls_manager_weak_ptr_->ScrollBy(delta);
+  top_controls_manager_weak_ptr_->ScrollEnd();
+}
+
+float LayerTreeHost::GetTopControlsOffset() {
+  return top_controls_manager_weak_ptr_->controls_top_offset();

[aelias_OOO_until_Jul13, 2013/05/21 05:51:41]

Not thread-safe either.  I don't think you really need this read anyway.

[Jinsuk Kim, 2013/05/24 09:57:13]

Right. removed.

+}
+
 void LayerTreeHost::DidLoseOutputSurface() {
   TRACE_EVENT0("cc", "LayerTreeHost::DidLoseOutputSurface");
   DCHECK(proxy_->IsMainThread());