bluetooth: Allow updates on chooser items.

content/public/browser/bluetooth_chooser.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 CONTENT_PUBLIC_BROWSER_BLUETOOTH_CHOOSER_H_
 #define CONTENT_PUBLIC_BROWSER_BLUETOOTH_CHOOSER_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 50 matching lines @@
   // Lets the chooser tell the user the state of the Bluetooth adapter. This
   // defaults to POWERED_ON.
   enum class AdapterPresence { ABSENT, POWERED_OFF, POWERED_ON };
   virtual void SetAdapterPresence(AdapterPresence presence) {}
 
   // Lets the chooser tell the user whether discovery is happening. This
   // defaults to DISCOVERING.
   enum class DiscoveryState { FAILED_TO_START, DISCOVERING, IDLE };
   virtual void ShowDiscoveryState(DiscoveryState state) {}
 
-  // Shows a new device in the chooser.
-  virtual void AddDevice(const std::string& device_id,
-                         const base::string16& device_name) {}
+  // Adds a new device to the chooser or updates the information of an existing
+  // device.
+  virtual void AddOrUpdateDevice(const std::string& device_id,

[juncai, 2016/08/04 21:52:25]

Does it make sense to have a separate function:
UpdateDevice()
instead of doing these two things in one function? This probably will also make
testing easier since we can test them separately.

[ortuno, 2016/08/05 02:16:09]

If we were to separate these two functions, chooser clients would have to keep
track of which devices they have already added which means yet another set of
device_ids. We could expose a HasDevice() function so that clients don't have to
keep track, but that would mean two extra functions HasDevice() and
UpdateDevice() that we have to implement all the way down to java.

[juncai, 2016/08/05 20:44:30]

Acknowledged.

+                                 const base::string16& device_name) {}
 
   // Tells the chooser that a device is no longer available. The chooser should
   // not call DeviceSelected() for a device that's been removed.
   virtual void RemoveDevice(const std::string& device_id) {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_BLUETOOTH_CHOOSER_H_