[VR, Permission] Use appopriate type parameters for WebCallbacks (1/3)

Source/modules/vr/VRHardwareUnitCollection.cpp

 // 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 "config.h"
 #include "modules/vr/VRHardwareUnitCollection.h"
 
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Navigator.h"
 #include "core/page/Page.h"
 #include "modules/vr/HMDVRDevice.h"
 #include "modules/vr/NavigatorVRDevice.h"
 #include "modules/vr/PositionSensorVRDevice.h"
 #include "modules/vr/VRController.h"
 #include "modules/vr/VRGetDevicesCallback.h"
 #include "modules/vr/VRHardwareUnit.h"
 #include "modules/vr/VRPositionState.h"
 
 namespace blink {
 
 VRHardwareUnitCollection::VRHardwareUnitCollection(VRController* controller)
     : m_controller(controller)
 {
 }
 
-HeapVector<Member<VRDevice>> VRHardwareUnitCollection::updateVRHardwareUnits(const WebVector<WebVRDevice>* devices)
+HeapVector<Member<VRDevice>> VRHardwareUnitCollection::updateVRHardwareUnits(const WebVector<WebVRDevice>& devices)
 {
     VRDeviceVector vrDevices;
 
-    if (!devices)
-        return vrDevices;
-
-    for (size_t i = 0; i < devices->size(); ++i) {
-        const WebVRDevice& device = (*devices)[i];
-
+    for (const auto& device : devices) {
         VRHardwareUnit* hardwareUnit = getHardwareUnitForIndex(device.index);
         if (!hardwareUnit) {
             hardwareUnit = new VRHardwareUnit(m_controller);
             m_hardwareUnits.append(hardwareUnit);
         }
 
         hardwareUnit->updateFromWebVRDevice(device);
         hardwareUnit->addDevicesToVector(vrDevices);
     }
 
@@ skipping 13 matching lines @@
     return 0;
 }
 
 DEFINE_TRACE(VRHardwareUnitCollection)
 {
     visitor->trace(m_controller);
     visitor->trace(m_hardwareUnits);
 }
 
 } // namespace blink