Support InputRouter recycling

content/browser/renderer_host/input/input_router_impl.h

Index: content/browser/renderer_host/input/input_router_impl.h
diff --git a/content/browser/renderer_host/input/input_router_impl.h b/content/browser/renderer_host/input/input_router_impl.h
index 0f7b023bfd6fe3e7233a5bd23e43d3d33acf0cee..c513b04d5ad660a9e4b505980cadfa4ef42e7a32 100644
--- a/content/browser/renderer_host/input/input_router_impl.h
+++ b/content/browser/renderer_host/input/input_router_impl.h
@@ -15,7 +15,6 @@
 #include "content/browser/renderer_host/input/touch_action_filter.h"
 #include "content/browser/renderer_host/input/touch_event_queue.h"
 #include "content/browser/renderer_host/input/touchpad_tap_suppression_controller.h"
-#include "content/common/input/input_event_stream_validator.h"
 #include "content/public/browser/native_web_keyboard_event.h"
 
 struct InputHostMsg_HandleInputEvent_ACK_Params;
@@ -31,6 +30,7 @@ struct LatencyInfo;
 namespace content {
 
 class InputAckHandler;
+class InputEventStreamValidator;
 class InputRouterClient;
 class OverscrollController;
 struct DidOverscrollParams;
@@ -46,6 +46,7 @@ class CONTENT_EXPORT InputRouterImpl
     Config();
     GestureEventQueue::Config gesture_config;
     TouchEventQueue::Config touch_config;
+    bool validate_event_stream;
   };
 
   InputRouterImpl(IPC::Sender* sender,
@@ -56,7 +57,6 @@ class CONTENT_EXPORT InputRouterImpl
   virtual ~InputRouterImpl();
 
   // InputRouter
-  virtual void Flush() override;
   virtual bool SendInput(scoped_ptr<IPC::Message> message) override;
   virtual void SendMouseEvent(
       const MouseEventWithLatencyInfo& mouse_event) override;
@@ -70,6 +70,8 @@ class CONTENT_EXPORT InputRouterImpl
       const GestureEventWithLatencyInfo& gesture_event) override;
   virtual void SendTouchEvent(
       const TouchEventWithLatencyInfo& touch_event) override;
+  virtual void Recycle() override;
+  virtual void RequestFlushedNotification() override;
   virtual const NativeWebKeyboardEvent* GetLastKeyboardEvent() const override;
   virtual bool ShouldForwardTouchEvent() const override;
   virtual void OnViewUpdated(int view_flags) override;
@@ -270,11 +272,17 @@ private:
   // to the client_ after all events have been dispatched/acked.
   bool flush_requested_;
 
+  // Whether we're in the scope of a |Recycle()| call. The only input events
+  // that should conceivably arrive when this is true are gesture events, which
+  // will be summarily dropped.
+  bool in_recycle_;
+
   TouchEventQueue touch_event_queue_;
   GestureEventQueue gesture_event_queue_;
   TouchActionFilter touch_action_filter_;
-  InputEventStreamValidator input_stream_validator_;
-  InputEventStreamValidator output_stream_validator_;
+
+  scoped_ptr<InputEventStreamValidator> optional_input_stream_validator_;
+  scoped_ptr<InputEventStreamValidator> optional_output_stream_validator_;
 
   DISALLOW_COPY_AND_ASSIGN(InputRouterImpl);
 };