avoid dereferencing NULL extension in ExtensionHost

BUG=chromium-os:13739
TEST=None

Review URL: http://codereview.chromium.org/6932038

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@84502 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index fede5d7..fca68a1 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -2042,7 +2042,7 @@
 void ExtensionService::DidCreateRenderViewForBackgroundPage(
     ExtensionHost* host) {
   OrphanedDevTools::iterator iter =
-      orphaned_dev_tools_.find(host->extension()->id());
+      orphaned_dev_tools_.find(host->extension_id());
   if (iter == orphaned_dev_tools_.end())
     return;