Added class BluetoothDeviceMac, returns mac device timing data

device/bluetooth/bluetooth_low_energy_device_mac.mm

 // 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_low_energy_device_mac.h"
 
 #import <CoreFoundation/CoreFoundation.h>
 
 #include "base/mac/scoped_cftyperef.h"
 #include "base/mac/sdk_forward_declarations.h"
@@ skipping 57 matching lines @@
     int rssi) {
   Update(peripheral, advertisementData, rssi);
 }
 
 BluetoothLowEnergyDeviceMac::~BluetoothLowEnergyDeviceMac() {
 }
 
 void BluetoothLowEnergyDeviceMac::Update(CBPeripheral* peripheral,
                                          NSDictionary* advertisementData,
                                          int rssi) {
+  last_update_time_.reset([[NSDate date] retain]);
   peripheral_.reset([peripheral retain]);
   rssi_ = rssi;
   ClearServiceData();
   NSNumber* nbConnectable =
       [advertisementData objectForKey:CBAdvertisementDataIsConnectable];
   connectable_ = [nbConnectable boolValue];
   NSDictionary* serviceData =
       [advertisementData objectForKey:CBAdvertisementDataServiceDataKey];
   for (CBUUID* uuid in serviceData) {
     NSData* data = [serviceData objectForKey:uuid];
@@ skipping 131 matching lines @@
     const ConnectToServiceErrorCallback& error_callback) {
   NOTIMPLEMENTED();
 }
 
 void BluetoothLowEnergyDeviceMac::CreateGattConnection(
     const GattConnectionCallback& callback,
     const ConnectErrorCallback& error_callback) {
   NOTIMPLEMENTED();
 }
 
+NSDate* BluetoothLowEnergyDeviceMac::GetLastUpdateTime() const {
+  return last_update_time_.get();
+}
+
 std::string BluetoothLowEnergyDeviceMac::GetDeviceName() const {
   return base::SysNSStringToUTF8([peripheral_ name]);
 }
 
 std::string BluetoothLowEnergyDeviceMac::GetPeripheralIdentifier(
     CBPeripheral* peripheral) {
   // TODO(dvh): Remove this once we moved to OSX SDK >= 10.9.
   if ([peripheral respondsToSelector:@selector(identifier)]) {
     // When -[CBPeripheral identifier] is available.
     NSUUID* uuid = [peripheral identifier];
     NSString* uuidString = [uuid UUIDString];
     return base::SysNSStringToUTF8(uuidString);
   }
 
   base::ScopedCFTypeRef<CFStringRef> str(
       CFUUIDCreateString(NULL, [peripheral UUID]));
   return SysCFStringRefToUTF8(str);
 }