[GCM] API update to allow only a single sender in registration

chrome/browser/services/gcm/gcm_client_mock.cc

Index: chrome/browser/services/gcm/gcm_client_mock.cc
diff --git a/chrome/browser/services/gcm/gcm_client_mock.cc b/chrome/browser/services/gcm/gcm_client_mock.cc
index 656fe558b366fe9eb15284a6bcef253227a7f59f..365a04d412a8542453e6e98b4f045d7a426f6f33 100644
--- a/chrome/browser/services/gcm/gcm_client_mock.cc
+++ b/chrome/browser/services/gcm/gcm_client_mock.cc
@@ -60,12 +60,12 @@ void GCMClientMock::CheckOut() {
 
 void GCMClientMock::Register(const std::string& app_id,
                              const std::string& cert,
-                             const std::vector<std::string>& sender_ids) {
+                             const std::string& sender_id) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 
   std::string registration_id;
   if (error_simulation_ == ALWAYS_SUCCEED)
-    registration_id = GetRegistrationIdFromSenderIds(sender_ids);
+    registration_id = GetRegistrationIdFromSenderIds(sender_id);
 
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
@@ -126,24 +126,13 @@ void GCMClientMock::DeleteMessages(const std::string& app_id) {
 
 // static
 std::string GCMClientMock::GetRegistrationIdFromSenderIds(
-    const std::vector<std::string>& sender_ids) {
-  // GCMProfileService normalizes the sender IDs by making them sorted.
-  std::vector<std::string> normalized_sender_ids = sender_ids;
-  std::sort(normalized_sender_ids.begin(), normalized_sender_ids.end());
-
-  // Simulate the registration_id by concaternating all sender IDs.
-  // Set registration_id to empty to denote an error if sender_ids contains a
+    const std::string& sender_id) {
+  // Simulate the registration_id by appending reg_id to the sender ID.
+  // Set registration_id to empty to denote an error if sender_id contains a
   // hint.
-  std::string registration_id;
-  if (sender_ids.size() != 1 ||
-      sender_ids[0].find("error") == std::string::npos) {
-    for (size_t i = 0; i < normalized_sender_ids.size(); ++i) {
-      if (i > 0)
-        registration_id += ",";
-      registration_id += normalized_sender_ids[i];
-    }
-  }
-  return registration_id;
+  if (sender_id.find("error") == std::string::npos)
+    return sender_id + "_reg_id";
+  return std::string();
 }
 
 void GCMClientMock::CheckinFinished() {