Handle touchpad flings with passive event listeners on compositor thread.

content/renderer/input/input_handler_manager.h

Index: content/renderer/input/input_handler_manager.h
diff --git a/content/renderer/input/input_handler_manager.h b/content/renderer/input/input_handler_manager.h
index c5ce6c34e1fb0252508aba20b4adfed1cc51c8c7..b838d9b3052b6f311fdd82854f7176cea02913b3 100644
--- a/content/renderer/input/input_handler_manager.h
+++ b/content/renderer/input/input_handler_manager.h
@@ -104,6 +104,12 @@ class CONTENT_EXPORT InputHandlerManager {
   // Called from the compositor's thread.
   void NeedsMainFrame(int routing_id);
 
+  // Called from the compositor's thread.
+  void DispatchNonBlockingEventToMainThread(
+      int routing_id,
+      ui::ScopedWebInputEvent event,
+      const ui::LatencyInfo& latency_info);
+
  private:
   // Called from the compositor's thread.
   void AddInputHandlerOnCompositorThread(