cc: Do not allow gesture-scrolling 'overflow[-{x|y}]:hidden' layers.

cc/layers/layer.cc

Index: cc/layers/layer.cc
diff --git a/cc/layers/layer.cc b/cc/layers/layer.cc
index 15de22340069d2ca2622db4f13b00f81338ade75..15e742eada497cb290faf2183e516f6c6099e598 100644
--- a/cc/layers/layer.cc
+++ b/cc/layers/layer.cc
@@ -41,6 +41,8 @@ Layer::Layer()
       scrollable_(false),
       should_scroll_on_main_thread_(false),
       have_wheel_event_handlers_(false),
+      user_scrollable_horizontal_(true),
+      user_scrollable_vertical_(true),
       anchor_point_(0.5f, 0.5f),
       background_color_(0),
       compositing_reasons_(kCompositingReasonUnknown),
@@ -833,6 +835,8 @@ void Layer::PushPropertiesTo(LayerImpl* layer) {
   DCHECK(!(TransformIsAnimating() && layer->TransformIsAnimatingOnImplOnly()));
 
   layer->SetScrollable(scrollable_);
+  layer->SetUserScrollable(user_scrollable_horizontal_,
+                           user_scrollable_vertical_);
   layer->SetMaxScrollOffset(max_scroll_offset_);
 
   LayerImpl* scroll_parent = NULL;