Allow MimeHandlerViewGuest be embedded inside OOPIFs

components/guest_view/browser/guest_view_manager.cc

 // Copyright 2014 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 "components/guest_view/browser/guest_view_manager.h"
 
 #include <tuple>
 #include <utility>
 
 #include "base/macros.h"
@@ skipping 445 matching lines @@
   // We might get some late arriving messages at tear down. Let's let the
   // embedder tear down in peace.
   auto it = guest_web_contents_by_instance_id_.find(guest_instance_id);
   if (it == guest_web_contents_by_instance_id_.end())
     return true;
 
   auto* guest_view = GuestViewBase::FromWebContents(it->second);
   if (!guest_view)
     return false;
 
+  if (guest_view->IsViewType("mimehandler")) {
+    // MimeHandlerViewGuests (PDF) may be embedded in a cross origin frame.
+    return embedder_render_process_id ==
+           guest_view->GetEmbedderFrame()->GetProcess()->GetID();

[nasko, 2016/10/27 21:03:40]

Why shouldn't this always be the case? Why make it view type specific?

[EhsanK, 2016/10/27 22:06:48]

I think other guests are not supposed to be embedded inside <iframe>. I can
remove this if there are no concerns about guest being embedded in <iframe>s.

+  }
+
   return embedder_render_process_id ==
-      guest_view->owner_web_contents()->GetRenderProcessHost()->GetID();
+         guest_view->owner_web_contents()->GetRenderProcessHost()->GetID();
 }
 
 GuestViewManager::ElementInstanceKey::ElementInstanceKey()
     : embedder_process_id(content::ChildProcessHost::kInvalidUniqueID),
       element_instance_id(content::ChildProcessHost::kInvalidUniqueID) {
 }
 
 GuestViewManager::ElementInstanceKey::ElementInstanceKey(
     int embedder_process_id,
     int element_instance_id)
@@ skipping 17 matching lines @@
     const GuestViewCreateFunction& create_function,
     const GuestViewCleanUpFunction& cleanup_function)
     : create_function(create_function), cleanup_function(cleanup_function) {}
 
 GuestViewManager::GuestViewData::GuestViewData(const GuestViewData& other) =
     default;
 
 GuestViewManager::GuestViewData::~GuestViewData() {}
 
 }  // namespace guest_view