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 060f7c58caf13a371144b179e09b88a4a65ce25c..c760c7467305366bb3cae55e87948901e0fdbb6f 100644
--- a/content/renderer/input/input_handler_manager.h
+++ b/content/renderer/input/input_handler_manager.h
@@ -11,6 +11,7 @@
 #include "content/common/content_export.h"
 #include "content/common/input/input_event_ack_state.h"
 #include "content/renderer/render_view_impl.h"
+#include "ui/events/blink/scoped_web_input_event.h"
 
 namespace base {
 class SingleThreadTaskRunner;
@@ -95,6 +96,12 @@ class CONTENT_EXPORT InputHandlerManager {
   // Called from the compositor's thread.
   void DidAnimateForInput();
 
+  // 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(