bluetooth: Refactor GetDescriptorForUUID to GetDescriptorsForUUID.

device/bluetooth/bluetooth_remote_gatt_characteristic_android.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "device/bluetooth/bluetooth_remote_gatt_characteristic_android.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/bind.h"
@@ skipping 137 matching lines @@
 
   if (!hasNotify && !hasIndicate) {
     LOG(ERROR) << "Characteristic needs NOTIFY or INDICATE";
     base::MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(error_callback,
                    BluetoothRemoteGattServiceAndroid::GATT_ERROR_FAILED));
     return;
   }
 
-  BluetoothGattDescriptor* descriptor = GetDescriptorForUUID(
+  std::vector<BluetoothGattDescriptor*> ccc_descriptor = GetDescriptorsForUUID(
       BluetoothGattDescriptor::ClientCharacteristicConfigurationUuid());
 
-  if (!descriptor) {
+  if (ccc_descriptor.size() != 1u) {

[ortuno, 2016/03/13 20:41:45]

Hmm this would fail with GATT NOT SUPPORTED if the characteristic has two ccc
descriptors. I'm OK with it failing with if there are 2 CCC descriptors but GATT
NOT SUPPORTED is misleading.

[scheib, 2016/03/25 00:13:57]

Done: Different errors returned for <1 and >1. Test added for multiple CCCDs.

     LOG(ERROR)
         << "Could not find client characteristic configuration descriptor";
     base::MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(error_callback,
                    BluetoothRemoteGattServiceAndroid::GATT_ERROR_FAILED));
     return;
   }
 
   if (!Java_ChromeBluetoothRemoteGattCharacteristic_setCharacteristicNotification(
           AttachCurrentThread(), j_characteristic_.obj(), true)) {
     LOG(ERROR) << "Error enabling characteristic notification";
     base::MessageLoop::current()->PostTask(
         FROM_HERE,
         base::Bind(error_callback,
                    BluetoothRemoteGattServiceAndroid::GATT_ERROR_FAILED));
     return;
   }
 
   std::vector<uint8_t> value;
   value.push_back(hasNotify ? 1 : 2);
   value.push_back(0);
 
   pending_start_notify_calls_.push(std::make_pair(callback, error_callback));
-  descriptor->WriteRemoteDescriptor(
+  ccc_descriptor[0]->WriteRemoteDescriptor(
       value, base::Bind(&BluetoothRemoteGattCharacteristicAndroid::
                             OnStartNotifySessionSuccess,
                         base::Unretained(this)),
       base::Bind(
           &BluetoothRemoteGattCharacteristicAndroid::OnStartNotifySessionError,
           base::Unretained(this)));
 }
 
 void BluetoothRemoteGattCharacteristicAndroid::ReadRemoteCharacteristic(
     const ValueCallback& callback,
@@ skipping 148 matching lines @@
 void BluetoothRemoteGattCharacteristicAndroid::EnsureDescriptorsCreated()
     const {
   if (!descriptors_.empty())
     return;
 
   Java_ChromeBluetoothRemoteGattCharacteristic_createDescriptors(
       AttachCurrentThread(), j_characteristic_.obj());
 }
 
 }  // namespace device