Check for a NULL Extension before dispatching events to it, to fix a crash.

BUG=66011
TEST=no


Review URL: http://codereview.chromium.org/7845032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@100965 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index 473c283..2cd6d79a 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -2014,6 +2014,7 @@
   // We allow the extension to see events and data from another profile iff it
   // uses "spanning" behavior and it has incognito access. "split" mode
   // extensions only see events for a matching profile.
+  CHECK(extension);
   return IsIncognitoEnabled(extension->id()) &&
       !extension->incognito_split_mode();
 }