GSB uses delta_hints to calculate scrolling chain.

ui/events/blink/input_handler_proxy_unittest.cc

Index: ui/events/blink/input_handler_proxy_unittest.cc
diff --git a/ui/events/blink/input_handler_proxy_unittest.cc b/ui/events/blink/input_handler_proxy_unittest.cc
index 2a9338503535f7f62090e1fc4b51952931537fae..39ddfd6722eac02a9e9dcaceb1ac3f3349e068b9 100644
--- a/ui/events/blink/input_handler_proxy_unittest.cc
+++ b/ui/events/blink/input_handler_proxy_unittest.cc
@@ -173,8 +173,7 @@ class MockInputHandler : public cc::InputHandler {
   MOCK_METHOD2(RootScrollBegin,
                ScrollStatus(cc::ScrollState*,
                             cc::InputHandler::ScrollInputType type));
-  MOCK_METHOD1(ScrollAnimatedBegin,
-               ScrollStatus(const gfx::Point& viewport_point));
+  MOCK_METHOD1(ScrollAnimatedBegin, ScrollStatus(cc::ScrollState*));
   MOCK_METHOD3(ScrollAnimated,
                ScrollStatus(const gfx::Point& viewport_point,
                             const gfx::Vector2dF& scroll_delta,