Allow MimeHandlerViewGuest be embedded inside OOPIFs

extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc

Index: extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc
diff --git a/extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc b/extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc
index 8da2fac73794c1f63072b9e68cdd7835f9af7643..b54006592ff5994490dccddb0e8444667af594bb 100644
--- a/extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc
+++ b/extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc
@@ -76,8 +76,10 @@ GuestViewBase* MimeHandlerViewGuest::Create(WebContents* owner_web_contents) {
 
 MimeHandlerViewGuest::MimeHandlerViewGuest(WebContents* owner_web_contents)
     : GuestView<MimeHandlerViewGuest>(owner_web_contents),
-      delegate_(ExtensionsAPIClient::Get()->CreateMimeHandlerViewGuestDelegate(
-          this)) {}
+      delegate_(
+          ExtensionsAPIClient::Get()->CreateMimeHandlerViewGuestDelegate(this)),
+      embedder_frame_process_id_(0),
+      embedder_frame_routing_id_(MSG_ROUTING_NONE) {}
 
 MimeHandlerViewGuest::~MimeHandlerViewGuest() {
 }
@@ -86,6 +88,21 @@ bool MimeHandlerViewGuest::CanUseCrossProcessFrames() {
   return false;
 }
 
+content::RenderFrameHost* MimeHandlerViewGuest::GetEmbedderFrame() {
+  if (embedder_frame_routing_id_ != MSG_ROUTING_NONE)
+    return content::RenderFrameHost::FromID(embedder_frame_process_id_,
+                                            embedder_frame_routing_id_);
+  return GuestViewBase::GetEmbedderFrame();
+}
+
+void MimeHandlerViewGuest::SetEmbedderFrame(int process_id, int routing_id) {
+  DCHECK_NE(routing_id, MSG_ROUTING_NONE);
+  DCHECK_EQ(embedder_frame_routing_id_, MSG_ROUTING_NONE);
+
+  embedder_frame_process_id_ = process_id;
+  embedder_frame_routing_id_ = routing_id;

[wjmaclean, 2016/10/20 14:47:22]

Do we need to do anything with these values when detaching the guest?

[EhsanK, 2016/10/20 21:41:18]

We could reset to 0 and MSG_ROUTING_NONE. But MimeHandlerViewGuest is destroyed
on detach.

Also, if guest outlives the frame, it is still fine since we check
GetEmbedderFrame() against nullptr when we use it. But I will take another look
to see if there are any potential hazards with these.

+}
+
 const char* MimeHandlerViewGuest::GetAPINamespace() const {
   return "mimeHandlerViewGuestInternal";
 }