SendPageMessage() should not send to a WebView guest's embedder.

content/browser/frame_host/render_frame_host_manager.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/frame_host/render_frame_host_manager.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <utility>
@@ skipping 2485 matching lines @@
     delete msg;
     return;
   }
 
   auto send_msg = [](IPC::Sender* sender, int routing_id, IPC::Message* msg) {
     IPC::Message* copy = new IPC::Message(*msg);
     copy->set_routing_id(routing_id);
     sender->Send(copy);
   };
 
-  for (const auto& pair : proxy_hosts_)
-    send_msg(pair.second.get(), pair.second->GetRoutingID(), msg);
+  // When sending a PageMessage to a WebView's guest, we don't want to also

[nasko, 2016/05/04 21:58:59]

nit: WebView is overloaded term, let's avoid using it, especially in content/,
which doesn't even have that concept. We have the inner/outer relationship we
can use here.

[wjmaclean, 2016/05/05 15:40:56]

Done.

+  // send it to the embedder's frames as well. A WebView guest frame tree should
+  // have no proxies other than for its embedder.
+  if (!ForInnerDelegate()) {

[nasko, 2016/05/04 21:58:59]

This will not be true if we allow cross-process navigations in GuestViews. Can
we instead compare the SiteInstance of the proxy with the SiteInstance of the
outer WebContents node?

[wjmaclean, 2016/05/05 15:40:56]

I'm not sure I understand this. What if some sub-frame to the inner contents has
the same SiteInstance as the outer WebContents? How would we differentiate them?

+    for (const auto& pair : proxy_hosts_)
+      send_msg(pair.second.get(), pair.second->GetRoutingID(), msg);
+  }
 
   if (speculative_render_frame_host_) {
     send_msg(speculative_render_frame_host_.get(),
              speculative_render_frame_host_->GetRoutingID(), msg);
   } else if (pending_render_frame_host_) {
     send_msg(pending_render_frame_host_.get(),
              pending_render_frame_host_->GetRoutingID(), msg);
   }
 
   msg->set_routing_id(render_frame_host_->GetRoutingID());
@@ skipping 29 matching lines @@
                                              resolved_url)) {
     DCHECK(!dest_instance ||
            dest_instance == render_frame_host_->GetSiteInstance());
     return false;
   }
 
   return true;
 }
 
 }  // namespace content