Add signal strength indicator icon to WebBluetooth chooser on non-Mac desktops

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 56 matching lines @@
   // defaults to DISCOVERING.
   enum class DiscoveryState { FAILED_TO_START, DISCOVERING, IDLE };
   virtual void ShowDiscoveryState(DiscoveryState state) {}
 
   // Adds a new device to the chooser or updates the information of an existing
   // device.
   //
   // Sometimes when a Bluetooth device stops advertising, the |device_name| can
   // be invalid, and in that case |should_update_name| will be set false.
   //
-  // Passing nullptr for |rssi| means that the device doesn't have RSSI which
-  // happens when the device is already connected.
+  // The range of |signal_strength_level| is -1 to 4 inclusively.
+  // -1 means that the device doesn't have RSSI which happens when the device
+  // is already connected.
   virtual void AddOrUpdateDevice(const std::string& device_id,
                                  bool should_update_name,
                                  const base::string16& device_name,
                                  bool is_gatt_connected,
                                  bool is_paired,
-                                 const int8_t* rssi) {}
+                                 int signal_strength_level) {}
 
   // 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_