Add 3 more registartion status codes for UMA collection. Also added tests.

google_apis/gcm/engine/registration_request.h

Index: google_apis/gcm/engine/registration_request.h
diff --git a/google_apis/gcm/engine/registration_request.h b/google_apis/gcm/engine/registration_request.h
index 293635001a6f326675ddfbf89d1e18eacf96bcda..40334d0e671946cb896b55c10196b68dd338de31 100644
--- a/google_apis/gcm/engine/registration_request.h
+++ b/google_apis/gcm/engine/registration_request.h
@@ -40,6 +40,9 @@ class GCM_EXPORT RegistrationRequest : public net::URLFetcherDelegate {
     AUTHENTICATION_FAILED,      // Authentication failed.
     DEVICE_REGISTRATION_ERROR,  // Chrome is not properly registered.
     UNKNOWN_ERROR,              // Unknown error.
+    URL_FETCHING_FAILED,        // URL fetching failed.
+    HTTP_NOT_OK,                // HTTP status was not OK.
+    RESPONSE_PARSING_FAILED,    // Registration response parsing failed.
     // NOTE: always keep this entry at the end. Add new status types only
     // immediately above this line. Make sure to update the corresponding
     // histogram enum accordingly.
@@ -91,6 +94,10 @@ class GCM_EXPORT RegistrationRequest : public net::URLFetcherDelegate {
   // failure, when |update_backoff| is true.
   void RetryWithBackoff(bool update_backoff);
 
+  // Parse the response returned by the URL fetcher into token, and returns the
+  // status.
+  Status ParseResponse(const net::URLFetcher* source, std::string* token);
+
   RegistrationCallback callback_;
   RequestInfo request_info_;