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

extensions/browser/guest_view/guest_view_base.cc

Index: extensions/browser/guest_view/guest_view_base.cc
diff --git a/extensions/browser/guest_view/guest_view_base.cc b/extensions/browser/guest_view/guest_view_base.cc
index 9a00f074796d8582282fb3b7168d53336e800feb..9c75225b3dd07bdba4889e33c0e4d3280b2dea75 100644
--- a/extensions/browser/guest_view/guest_view_base.cc
+++ b/extensions/browser/guest_view/guest_view_base.cc
@@ -262,8 +262,8 @@ void GuestViewBase::InitWithWebContents(
   create_params.GetInteger(guestview::kParameterInstanceId,
                            &view_instance_id_);
 
-  if (CanRunInDetachedState())
-    SetUpSizing(create_params);
+  //if (CanRunInDetachedState())
+  //  SetUpSizing(create_params);
 
   // Give the derived class an opportunity to perform additional initialization.
   DidInitialize(create_params);
@@ -424,8 +424,8 @@ content::WebContents* GuestViewBase::CreateNewGuestWindow(
 }
 
 void GuestViewBase::DidAttach(int guest_proxy_routing_id) {
-  DCHECK(guest_proxy_routing_id_ == MSG_ROUTING_NONE ||
-         guest_proxy_routing_id == guest_proxy_routing_id_);
+  //DCHECK(guest_proxy_routing_id_ == MSG_ROUTING_NONE ||
+  //       guest_proxy_routing_id == guest_proxy_routing_id_);
   guest_proxy_routing_id_ = guest_proxy_routing_id;
 
   opener_lifetime_observer_.reset();