Cleanup RemotePlatformLayer when disconnecting RemoteFrame.

Source/core/page/EventHandler.cpp

Index: Source/core/page/EventHandler.cpp
diff --git a/Source/core/page/EventHandler.cpp b/Source/core/page/EventHandler.cpp
index 2028579e2f4b0e0dd5ca1d31cf4c90b38a3c08e7..c8c1eb50d83d9ecf6377bdbddca1d290ba439cd1 100644
--- a/Source/core/page/EventHandler.cpp
+++ b/Source/core/page/EventHandler.cpp
@@ -981,10 +981,6 @@ static LocalFrame* subframeForTargetNode(Node* node)
     if (!renderer || !renderer->isRenderPart())
         return nullptr;
 
-    // FIXME: This explicit check is needed only until RemoteFrames have RemoteFrameViews.
-    if (isHTMLFrameElementBase(node) && toHTMLFrameElementBase(node)->contentFrame() && toHTMLFrameElementBase(node)->contentFrame()->isRemoteFrameTemporary())
-        return nullptr;
-
     Widget* widget = toRenderPart(renderer)->widget();
     if (!widget || !widget->isFrameView())
         return nullptr;