Move compositor thread input handling logic into content

cc/input/input_handler.h

Index: cc/input/input_handler.h
diff --git a/cc/input/input_handler.h b/cc/input/input_handler.h
index b3f805e85c9fa5261608f80fb36944cfc69de8e0..2c73710cd860ed470ba9904ef5201ca5f0674c48 100644
--- a/cc/input/input_handler.h
+++ b/cc/input/input_handler.h
@@ -21,6 +21,21 @@ namespace cc {
 
 class LayerScrollOffsetDelegate;
 
+class CC_EXPORT InputHandlerClient {
+ public:
+  virtual ~InputHandlerClient() {}
+
+  virtual void WillShutdown() = 0;
+  virtual void Animate(base::TimeTicks time) = 0;
+  virtual void MainThreadHasStoppedFlinging() = 0;
+
+ protected:
+  InputHandlerClient() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(InputHandlerClient);
+};
+
 // The InputHandler is a way for the embedders to interact with the impl thread
 // side of the compositor implementation. There is one InputHandler per
 // LayerTreeHost. To use the input handler, implement the InputHanderClient
@@ -30,6 +45,11 @@ class CC_EXPORT InputHandler {
   enum ScrollStatus { ScrollOnMainThread, ScrollStarted, ScrollIgnored };
   enum ScrollInputType { Gesture, Wheel, NonBubblingGesture };
 
+  // Binds a client to this handler to receive notifications. Only one client
+  // can be bound to an InputHandler. The client must live at least until the
+  // handler calls WillShutdown() on the client.
+  virtual void BindToClient(InputHandlerClient* client) = 0;
+
   // Selects a layer to be scrolled at a given point in viewport (logical
   // pixel) coordinates. Returns ScrollStarted if the layer at the coordinates
   // can be scrolled, ScrollOnMainThread if the scroll event should instead be
@@ -100,21 +120,6 @@ class CC_EXPORT InputHandler {
   DISALLOW_COPY_AND_ASSIGN(InputHandler);
 };
 
-class CC_EXPORT InputHandlerClient {
- public:
-  virtual ~InputHandlerClient() {}
-
-  virtual void BindToHandler(InputHandler* handler) = 0;
-  virtual void Animate(base::TimeTicks time) = 0;
-  virtual void MainThreadHasStoppedFlinging() = 0;
-
- protected:
-  InputHandlerClient() {}
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(InputHandlerClient);
-};
-
 }  // namespace cc
 
 #endif  // CC_INPUT_INPUT_HANDLER_H_