bluetooth: Refactor GetDescriptorForUUID to GetDescriptorsForUUID.

device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc

Index: device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc
diff --git a/device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc b/device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc
index bb7e6696e7e55bfd7a930321243befbdd1541970..ae2c304d6216a5c7cb74629846bdcb64f9aa1773 100644
--- a/device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc
+++ b/device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc
@@ -137,7 +137,8 @@ void BluetoothRemoteGattCharacteristicAndroid::StartNotifySession(
     const NotifySessionCallback& callback,
     const ErrorCallback& error_callback) {
   if (!pending_start_notify_calls_.empty()) {
-    pending_start_notify_calls_.push(std::make_pair(callback, error_callback));
+    pending_start_notify_calls_.push_back(
+        std::make_pair(callback, error_callback));
     return;
   }
 
@@ -182,7 +183,8 @@ void BluetoothRemoteGattCharacteristicAndroid::StartNotifySession(
   value.push_back(hasNotify ? 1 : 2);
   value.push_back(0);
 
-  pending_start_notify_calls_.push(std::make_pair(callback, error_callback));
+  pending_start_notify_calls_.push_back(
+      std::make_pair(callback, error_callback));
   descriptor->WriteRemoteDescriptor(
       value, base::Bind(&BluetoothRemoteGattCharacteristicAndroid::
                             OnStartNotifySessionSuccess,
@@ -252,21 +254,23 @@ void BluetoothRemoteGattCharacteristicAndroid::OnChanged(
 }
 
 void BluetoothRemoteGattCharacteristicAndroid::OnStartNotifySessionSuccess() {
-  while (!pending_start_notify_calls_.empty()) {
-    PendingStartNotifyCall callbacks = pending_start_notify_calls_.front();
-    pending_start_notify_calls_.pop();
+  std::vector<PendingStartNotifyCall> reentrant_safe_callbacks;
+  reentrant_safe_callbacks.swap(pending_start_notify_calls_);
+
+  for (const auto& callback_pair : reentrant_safe_callbacks) {
     scoped_ptr<device::BluetoothGattNotifySession> notify_session(
         new BluetoothGattNotifySessionAndroid(instance_id_));
-    callbacks.first.Run(std::move(notify_session));
+    callback_pair.first.Run(std::move(notify_session));
   }
 }
 
 void BluetoothRemoteGattCharacteristicAndroid::OnStartNotifySessionError(
     BluetoothGattService::GattErrorCode error) {
-  while (!pending_start_notify_calls_.empty()) {
-    PendingStartNotifyCall callbacks = pending_start_notify_calls_.front();
-    pending_start_notify_calls_.pop();
-    callbacks.second.Run(error);
+  std::vector<PendingStartNotifyCall> reentrant_safe_callbacks;
+  reentrant_safe_callbacks.swap(pending_start_notify_calls_);
+
+  for (auto const& callback_pair : reentrant_safe_callbacks) {
+    callback_pair.second.Run(error);
   }
 }