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

cc/layers/layer_impl.h

 // 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.
 
 #ifndef CC_LAYERS_LAYER_IMPL_H_
 #define CC_LAYERS_LAYER_IMPL_H_
 
 #include <set>
 #include <string>
 
@@ skipping 356 matching lines @@
   void SetSentScrollDelta(gfx::Vector2d sent_scroll_delta);
   gfx::Vector2d sent_scroll_delta() const { return sent_scroll_delta_; }
 
   // Returns the delta of the scroll that was outside of the bounds of the
   // initial scroll
   gfx::Vector2dF ScrollBy(gfx::Vector2dF scroll);
 
   void SetScrollable(bool scrollable) { scrollable_ = scrollable; }
   bool scrollable() const { return scrollable_; }
 
+  void set_user_scrollable_horizontal(bool scrollable) {
+    user_scrollable_horizontal_ = scrollable;
+  }
+  void set_user_scrollable_vertical(bool scrollable) {
+    user_scrollable_vertical_ = scrollable;
+  }
+
   void ApplySentScrollDeltasFromAbortedCommit();
   void ApplyScrollDeltasSinceBeginFrame();
 
   void SetShouldScrollOnMainThread(bool should_scroll_on_main_thread) {
     should_scroll_on_main_thread_ = should_scroll_on_main_thread;
   }
   bool should_scroll_on_main_thread() const {
     return should_scroll_on_main_thread_;
   }
 
@@ skipping 150 matching lines @@
 
   // Properties synchronized from the associated Layer.
   gfx::PointF anchor_point_;
   float anchor_point_z_;
   gfx::Size bounds_;
   gfx::Vector2d scroll_offset_;
   LayerScrollOffsetDelegate* scroll_offset_delegate_;
   bool scrollable_;
   bool should_scroll_on_main_thread_;
   bool have_wheel_event_handlers_;
+  bool user_scrollable_horizontal_;
+  bool user_scrollable_vertical_;
   Region non_fast_scrollable_region_;
   Region touch_event_handler_region_;
   SkColor background_color_;
   bool stacking_order_changed_;
 
   // Whether the "back" of this layer should draw.
   bool double_sided_;
 
   // Tracks if drawing-related properties have changed since last redraw.
   bool layer_property_changed_;
@@ skipping 61 matching lines @@
   // Group of properties that need to be computed based on the layer tree
   // hierarchy before layers can be drawn.
   DrawProperties<LayerImpl> draw_properties_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_IMPL_H_