Fix a compile error caused in some compiler.

This switch covers all state, however, some compiler may cause
errors for no return statement after switch().

BUG=395633
R=flackr@chromium.org, sadrul@chromium.org
TEST=compile

Review URL: https://codereview.chromium.org/404153002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284456 0039d316-1c4b-4281-b951-d872f2087c98

athena/home/home_card_impl.cc

@@ -199,9 +199,10 @@ class HomeCardImpl : public HomeCard,
       case VISIBLE_MINIMIZED:
         return kHomeCardMinimizedHeight;
       case HIDDEN:
-        NOTREACHED();
-        return -1;
+        break;
     }
+    NOTREACHED();
+    return -1;
   }
 
   virtual int GetHorizontalMargin() const OVERRIDE {