Push API: Fix unsubscribing from GCM on Android

components/gcm_driver/gcm_driver.cc

Index: components/gcm_driver/gcm_driver.cc
diff --git a/components/gcm_driver/gcm_driver.cc b/components/gcm_driver/gcm_driver.cc
index a82e7b1bcff9e284809f57530eef878fea907d35..f9187b54027e1a6adb93f587d751d49869a4833a 100644
--- a/components/gcm_driver/gcm_driver.cc
+++ b/components/gcm_driver/gcm_driver.cc
@@ -69,8 +69,12 @@ void GCMDriver::Register(const std::string& app_id,
 }
 
 void GCMDriver::Unregister(const std::string& app_id,
+                           const std::vector<std::string>& sender_ids,
                            const UnregisterCallback& callback) {
   DCHECK(!app_id.empty());
+#if defined(OS_ANDROID)
+  DCHECK(!sender_ids.empty());
+#endif
   DCHECK(!callback.is_null());
 
   GCMClient::Result result = EnsureStarted(GCMClient::IMMEDIATE_START);
@@ -86,9 +90,13 @@ void GCMDriver::Unregister(const std::string& app_id,
     return;
   }
 
+  // Normalize 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());
+
   unregister_callbacks_[app_id] = callback;
 
-  UnregisterImpl(app_id);
+  UnregisterImpl(app_id, normalized_sender_ids);
 }
 
 void GCMDriver::Send(const std::string& app_id,