Handling of multiple concurrent requests from different clients in OAuth2TokenService

google_apis/gaia/oauth2_access_token_fetcher.cc

Index: google_apis/gaia/oauth2_access_token_fetcher.cc
diff --git a/google_apis/gaia/oauth2_access_token_fetcher.cc b/google_apis/gaia/oauth2_access_token_fetcher.cc
index 456251f0134cf627ae70b4c3d73dc6d639b6b9b8..08ed3c0d92c01b51b9e1facbc110b3e26b75b6fe 100644
--- a/google_apis/gaia/oauth2_access_token_fetcher.cc
+++ b/google_apis/gaia/oauth2_access_token_fetcher.cc
@@ -60,9 +60,10 @@ static URLFetcher* CreateFetcher(URLRequestContextGetter* getter,
                                  const GURL& url,
                                  const std::string& body,
                                  URLFetcherDelegate* delegate) {
+  static int fetcher_index = 0;
   bool empty_body = body.empty();
   URLFetcher* result = net::URLFetcher::Create(
-      0, url,
+      fetcher_index++, url,
       empty_body ? URLFetcher::GET : URLFetcher::POST,
       delegate);