Do not allow GuestViewManager to (re)use an instance ID that was already removed.

chrome/browser/guest_view/guest_view_base.cc

Index: chrome/browser/guest_view/guest_view_base.cc
diff --git a/chrome/browser/guest_view/guest_view_base.cc b/chrome/browser/guest_view/guest_view_base.cc
index 574730522f5ef44db091f2eee10946697244598d..9f3eba71569e1a8a911b595166fb61513be11f95 100644
--- a/chrome/browser/guest_view/guest_view_base.cc
+++ b/chrome/browser/guest_view/guest_view_base.cc
@@ -52,8 +52,8 @@ GuestViewBase::GuestViewBase(int guest_instance_id,
       weak_ptr_factory_(this) {
   webcontents_guestview_map.Get().insert(
       std::make_pair(guest_web_contents, this));
-  GuestViewManager::FromBrowserContext(browser_context_)->
-      AddGuest(guest_instance_id_, guest_web_contents);
+  DCHECK(GuestViewManager::FromBrowserContext(browser_context_)

[lazyboy, 2014/05/22 15:59:31]

Q: Do we need a CHECK here too?

[Fady Samuel, 2014/05/22 17:41:53]

If we have a CHECK inside AddGuest then why do we need a return value?

[lazyboy, 2014/05/22 18:34:45]

The return value was for test, I've moved the logic to a separate function and
testing that instead.
Changed back to return void.

+             ->AddGuest(guest_instance_id_, guest_web_contents));
 }
 
 // static