use enum to specify deviceSource for fling animation

public/platform/Platform.h

Index: public/platform/Platform.h
diff --git a/public/platform/Platform.h b/public/platform/Platform.h
index ffc958c304dd10497fd0485350590bfb6e9bf3c7..d3c17af2ec88b4d0b36e0069f5f1c4c1b933d157 100644
--- a/public/platform/Platform.h
+++ b/public/platform/Platform.h
@@ -594,17 +594,7 @@ public:
 
     // Creates a new fling animation curve instance for device |deviceSource|
     // with |velocity| and already scrolled |cumulativeScroll| pixels.
-    virtual WebGestureCurve* createFlingAnimationCurve(int deviceSource, const WebFloatPoint& velocity, const WebSize& cumulativeScroll) { return 0; }
-
-    // TODO(rjkroege): Remove at end of http://crbug.com/343327
-    virtual WebGestureCurve* createFlingAnimationCurve(
-        WebGestureDevice deviceSource,
-        const WebFloatPoint& velocity,
-        const WebSize& cumulativeScroll)
-    {
-        return createFlingAnimationCurve(
-            (int)deviceSource, velocity, cumulativeScroll);
-    }
+    virtual WebGestureCurve* createFlingAnimationCurve(WebGestureDevice deviceSource, const WebFloatPoint& velocity, const WebSize& cumulativeScroll) { return 0; }
 
     // WebRTC ----------------------------------------------------------