Move compositor InputHandler from RenderViewImpl to RenderWidget.

content/renderer/render_widget.h

Index: content/renderer/render_widget.h
diff --git a/content/renderer/render_widget.h b/content/renderer/render_widget.h
index 59a079c96a2cf3cdf410dc743a1f6783a3bde418..cac9876645ddffd7e1c17dbbf7ef1e72e5109b9c 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -19,6 +19,7 @@
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
@@ -69,6 +70,7 @@ namespace blink {
 namespace scheduler {
 class RenderWidgetSchedulingState;
 }
+struct WebActiveWheelFlingParameters;
 struct WebDeviceEmulationParams;
 class WebDragData;
 class WebFrameWidget;
@@ -412,6 +414,9 @@ class CONTENT_EXPORT RenderWidget
   // Helper to convert |point| using ConvertWindowToViewport().
   gfx::Point ConvertWindowPointToViewport(const gfx::Point& point);
 
+  virtual void TransferActiveWheelFlingAnimation(
+      const blink::WebActiveWheelFlingParameters& params) {}
+
  protected:
   // Friend RefCounted so that the dtor can be non-public. Using this class
   // without ref-counting is an error.
@@ -786,6 +791,8 @@ class CONTENT_EXPORT RenderWidget
   // Wraps the |webwidget_| as a MouseLockDispatcher::LockTarget interface.
   std::unique_ptr<MouseLockDispatcher::LockTarget> webwidget_mouse_lock_target_;
 
+  bool has_added_input_handler_;
+
  private:
   // Applies/Removes the DevTools device emulation transformation to/from a
   // window rect.
@@ -837,6 +844,8 @@ class CONTENT_EXPORT RenderWidget
   // session, this info is sent to the browser along with other drag/drop info.
   DragEventSourceInfo possible_drag_event_info_;
 
+  base::WeakPtrFactory<RenderWidget> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);
 };