Remove renderer-to-renderer input event forwarding for OOPIFs

content/renderer/render_frame_proxy.h

Index: content/renderer/render_frame_proxy.h
diff --git a/content/renderer/render_frame_proxy.h b/content/renderer/render_frame_proxy.h
index f58a0cbd9ff2f75e0ce05d9658460913e243bb91..d1dc511bd5c0ead4ab0af263c85df39d6ec00f88 100644
--- a/content/renderer/render_frame_proxy.h
+++ b/content/renderer/render_frame_proxy.h
@@ -17,7 +17,6 @@
 #include "url/origin.h"
 
 namespace blink {
-class WebInputEvent;
 struct WebRect;
 }
 
@@ -136,7 +135,6 @@ class CONTENT_EXPORT RenderFrameProxy
                           blink::WebDOMMessageEvent event) override;
   void navigate(const blink::WebURLRequest& request,
                 bool should_replace_current_entry) override;
-  void forwardInputEvent(const blink::WebInputEvent* event) override;
   void frameRectsChanged(const blink::WebRect& frame_rect) override;
   void updateRemoteViewportIntersection(
       const blink::WebRect& viewportIntersection) override;