Address some TODOs for ChooserBubbleDelegate class

chrome/browser/usb/usb_chooser_bubble_delegate.h

 // 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.
 
 #ifndef CHROME_BROWSER_USB_USB_CHOOSER_BUBBLE_DELEGATE_H_
 #define CHROME_BROWSER_USB_USB_CHOOSER_BUBBLE_DELEGATE_H_
 
+#include <utility>
+
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
 #include "chrome/browser/ui/website_settings/chooser_bubble_delegate.h"
 #include "components/bubble/bubble_reference.h"
 #include "components/webusb/public/interfaces/webusb_permission_bubble.mojom.h"
 #include "device/usb/usb_service.h"
 #include "mojo/public/cpp/bindings/array.h"
 
@@ skipping 13 matching lines @@
                                  public device::UsbService::Observer {
  public:
   UsbChooserBubbleDelegate(
       Browser* browser,
       mojo::Array<device::usb::DeviceFilterPtr> device_filters,
       content::RenderFrameHost* render_frame_host,
       const webusb::WebUsbPermissionBubble::GetPermissionCallback& callback);
   ~UsbChooserBubbleDelegate() override;
 
   // ChooserBubbleDelegate:
-  const std::vector<base::string16>& GetOptions() const override;
-  void Select(int index) override;
+  size_t NumOptions() const override;
+  const base::string16& GetOption(size_t index) const override;
+  void Select(size_t index) override;
   void Cancel() override;
   void Close() override;
 
   // device::UsbService::Observer:
   void OnDeviceAdded(scoped_refptr<device::UsbDevice> device) override;
   void OnDeviceRemoved(scoped_refptr<device::UsbDevice> device) override;
 
   void GotUsbDeviceList(
       const std::vector<scoped_refptr<device::UsbDevice>>& devices);
 
   void set_bubble_controller(BubbleReference bubble_controller);
 
  private:
   content::RenderFrameHost* const render_frame_host_;
   webusb::WebUsbPermissionBubble::GetPermissionCallback callback_;
   ScopedObserver<device::UsbService, device::UsbService::Observer>
       usb_service_observer_;
   std::vector<device::UsbDeviceFilter> filters_;
-  std::vector<scoped_refptr<device::UsbDevice>> devices_;
-  std::vector<base::string16> devices_names_;
+  // The vector contains device object and device name pair for the
+  // same device.

[Peter Kasting, 2016/01/04 21:02:52]

Nit: How about:

Each pair is a (device, device name).

[juncai, 2016/01/04 22:44:47]

Done.

+  std::vector<std::pair<scoped_refptr<device::UsbDevice>, base::string16>>
+      devices_;
   BubbleReference bubble_controller_;
   base::WeakPtrFactory<UsbChooserBubbleDelegate> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UsbChooserBubbleDelegate);
 };
 
 #endif  // CHROME_BROWSER_USB_USB_CHOOSER_BUBBLE_DELEGATE_H_