Refactor Scroll Customization to share cc::ScrollStateData with blink.

cc/input/scroll_state.h

Index: cc/input/scroll_state.h
diff --git a/cc/input/scroll_state.h b/cc/input/scroll_state.h
index d704ecb55be91dccbffc3e08077a80836aaffd98..d475a32b9651442c341a1f2d2eb3c4dc8b2a23f2 100644
--- a/cc/input/scroll_state.h
+++ b/cc/input/scroll_state.h
@@ -43,8 +43,8 @@ class CC_EXPORT ScrollState {
               bool is_in_inertial_phase,
               bool is_ending,
               bool should_propagate = false,
-              bool delta_consumed_for_scroll_sequence = false,
-              bool is_direct_manipulation = false);
+              bool is_direct_manipulation = false,
+              bool delta_consumed_for_scroll_sequence = false);
   explicit ScrollState(ScrollStateData data);
   ~ScrollState();
 
@@ -89,11 +89,11 @@ class CC_EXPORT ScrollState {
   }
 
   void set_current_native_scrolling_layer(LayerImpl* layer) {
-    data_.current_native_scrolling_layer = layer;
+    data_.set_current_native_scrolling_layer(layer);
   }
 
   LayerImpl* current_native_scrolling_layer() const {
-    return data_.current_native_scrolling_layer;
+    return data_.current_native_scrolling_layer();
   }
 
   bool delta_consumed_for_scroll_sequence() const {