Remove GestureEventFilter and clean up related bits assuming that we turn on

content/browser/renderer_host/input/fling/flinger.h

Index: content/browser/renderer_host/input/fling/flinger.h
diff --git a/content/browser/renderer_host/input/fling/flinger.h b/content/browser/renderer_host/input/fling/flinger.h
index f7e1453ed624ab12f5a82eeb743e6a77a9f16c70..74504c4ba06c3a72f22a2d3980bdf86e24467282 100644
--- a/content/browser/renderer_host/input/fling/flinger.h
+++ b/content/browser/renderer_host/input/fling/flinger.h
@@ -15,6 +15,7 @@
 
 namespace content {
 class FlingerTest;
+class MockRenderWidgetHost;
 
 class FlingHelper {
  public:
@@ -49,6 +50,7 @@ class CONTENT_EXPORT Flinger : public FlingCurveTarget {
 
  private:
   friend class FlingerTest;
+  friend class MockRenderWidgetHost;
 
   // Overridden from FlingCurveTarget.
   virtual void ScrollBy(const gfx::PointF& delta) OVERRIDE;