[exp] Browser-side fling.

content/browser/renderer_host/input/input_router_impl.h

Index: content/browser/renderer_host/input/input_router_impl.h
diff --git a/content/browser/renderer_host/input/input_router_impl.h b/content/browser/renderer_host/input/input_router_impl.h
index ed648f50ce622d9baf95002b520757b154a9a0e7..e1e376bc7bdf1b532e236d6aeffb211a951cc08a 100644
--- a/content/browser/renderer_host/input/input_router_impl.h
+++ b/content/browser/renderer_host/input/input_router_impl.h
@@ -20,16 +20,41 @@
 
 struct InputHostMsg_HandleInputEvent_ACK_Params;
 
+#if defined(OS_ANDROID)
+namespace gfx {
+class Scroller;
+}
+#endif
+
 namespace IPC {
 class Sender;
 }
 
 namespace ui {
+class FlingCurve;
 struct LatencyInfo;
 }
 
 namespace content {
 
+class Flinger {
+ public:
+  explicit Flinger(const blink::WebGestureEvent& fling_event);
+  virtual ~Flinger();
+
+  blink::WebGestureEvent GetNextScrollEvent();
+
+ private:
+  blink::WebGestureEvent fling_event_;
+#if defined(OS_ANDROID)
+  scoped_ptr<gfx::Scroller> scroller_;
+#else
+  scoped_ptr<ui::FlingCurve> fling_curve_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(Flinger);
+};
+
 class InputAckHandler;
 class InputRouterClient;
 class OverscrollController;
@@ -276,6 +301,8 @@ private:
   InputEventStreamValidator input_stream_validator_;
   InputEventStreamValidator output_stream_validator_;
 
+  scoped_ptr<Flinger> flinger_;
+
   DISALLOW_COPY_AND_ASSIGN(InputRouterImpl);
 };