Adding run_at to chrome.tabs.executeScript/insertCss.

chrome/common/extensions/user_script.h

Index: chrome/common/extensions/user_script.h
diff --git a/chrome/common/extensions/user_script.h b/chrome/common/extensions/user_script.h
index 47b0287e3db0d8f1cf79db74432e9db4b94e839c..a50a9514f726fdbcd52a7b154a4eb760382f072e 100644
--- a/chrome/common/extensions/user_script.h
+++ b/chrome/common/extensions/user_script.h
@@ -39,6 +39,7 @@ class UserScript {
 
   // Locations that user scripts can be run inside the document.
   enum RunLocation {
+    UNDEFINED,
     DOCUMENT_START,  // After the documentElemnet is created, but before
                      // anything else happens.
     DOCUMENT_END,  // After the entire document is parsed. Same as
@@ -47,7 +48,6 @@ class UserScript {
                     // is "idle". Currently this uses the simple heuristic of:
                     // min(DOM_CONTENT_LOADED + TIMEOUT, ONLOAD), but no
                     // particular injection point is guaranteed.
-
     RUN_LOCATION_LAST  // Leave this as the last item.
   };