Make <webview> use out-of-process iframe architecture.

components/guest_view/browser/guest_view_message_filter.cc

 // Copyright 2015 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_message_filter.h"
 
 #include "components/guest_view/browser/guest_view_base.h"
 #include "components/guest_view/browser/guest_view_manager.h"
 #include "components/guest_view/browser/guest_view_manager_delegate.h"
 #include "components/guest_view/common/guest_view_messages.h"
@@ skipping 56 matching lines @@
 void GuestViewMessageFilter::OnDestruct() const {
   // Destroy the filter on the IO thread since that's where its weak pointers
   // are being used.
   BrowserThread::DeleteOnIOThread::Destruct(this);
 }
 
 bool GuestViewMessageFilter::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(GuestViewMessageFilter, message)
     IPC_MESSAGE_HANDLER(GuestViewHostMsg_AttachGuest, OnAttachGuest)
+    IPC_MESSAGE_HANDLER(GuestViewHostMsg_AttachToEmbedderFrame,
+                        OnAttachToEmbedderFrame)
     IPC_MESSAGE_HANDLER(GuestViewHostMsg_ViewCreated, OnViewCreated)
     IPC_MESSAGE_HANDLER(GuestViewHostMsg_ViewGarbageCollected,
                         OnViewGarbageCollected)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void GuestViewMessageFilter::OnViewCreated(int view_instance_id,
                                            const std::string& view_type) {
@@ skipping 18 matching lines @@
   // embedder is misbehaving.
   if (!manager)
     return;
 
   manager->AttachGuest(render_process_id_,
                        element_instance_id,
                        guest_instance_id,
                        params);
 }
 
+void GuestViewMessageFilter::OnAttachToEmbedderFrame(
+    int embedder_local_render_frame_id,
+    int element_instance_id,
+    int guest_instance_id,
+    const base::DictionaryValue& params) {
+  auto* manager = GuestViewManager::FromBrowserContext(browser_context_);
+  DCHECK(manager);
+  content::WebContents* guest_web_contents =
+      manager->GetGuestByInstanceIDSafely(guest_instance_id,
+                                          render_process_id_);
+  DCHECK(guest_web_contents);

[Fady Samuel, 2015/06/24 22:01:10]

I would consider CHECK'ing here. If the above fails, then the embedder is likely
malicious. Alternatively exit early, as the embedder will be killed anyway.

[lazyboy, 2015/06/24 23:01:50]

I'm doing early exit.
Done.

+  auto* guest = GuestViewBase::FromWebContents(guest_web_contents);
+  DCHECK(guest);
+  content::WebContents* owner_web_contents = guest->owner_web_contents();
+  DCHECK(owner_web_contents);
+  auto* embedder_frame = RenderFrameHost::FromID(
+      render_process_id_, embedder_local_render_frame_id);
+  guest_web_contents->AttachToOuterWebContentsFrame(owner_web_contents,

[Fady Samuel, 2015/06/24 22:01:10]

Comment above this explaining briefly what it does.

[lazyboy, 2015/06/24 23:01:50]

Done.

+                                                    embedder_frame);
+
+  manager->AttachGuest(render_process_id_, element_instance_id,

[Fady Samuel, 2015/06/24 22:01:10]

Comment above this explaining briefly what it does. Two calls to "Attach*" sound
similar, it's useful to document the differences.

[lazyboy, 2015/06/24 23:01:50]

Done.

+                       guest_instance_id, params);
+
+  owner_web_contents->GetMainFrame()->Send(
+      new GuestViewMsg_AttachToEmbedderFrame_ACK(element_instance_id));
+
+  guest->WillAttach(
+      owner_web_contents, element_instance_id, false,
+      base::Bind(&GuestViewMessageFilter::WillAttachCallback, this, guest));

[Fady Samuel, 2015/06/24 22:01:10]

nit: Can you bind directly?  base::Bind(&GuestViewBase::DidAttach, guest,
MSG_ROUTING_NONE)?

[lazyboy, 2015/06/24 23:01:50]

passing |guest| as |this| wouldn't work as |guest| is a raw GuestViewBase
pointer.

+}
+
+void GuestViewMessageFilter::WillAttachCallback(GuestViewBase* guest) {
+  guest->DidAttach(MSG_ROUTING_NONE);
+}
+
 }  // namespace guest_view