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

chrome/browser/ui/bluetooth/bluetooth_chooser_controller.h

Index: chrome/browser/ui/bluetooth/bluetooth_chooser_controller.h
diff --git a/chrome/browser/ui/bluetooth/bluetooth_chooser_controller.h b/chrome/browser/ui/bluetooth/bluetooth_chooser_controller.h
index 55f655e7b4df4608a889152a0746ef6552147cb1..e2c7c2c66572caada309eb24b0ce00863f70607b 100644
--- a/chrome/browser/ui/bluetooth/bluetooth_chooser_controller.h
+++ b/chrome/browser/ui/bluetooth/bluetooth_chooser_controller.h
@@ -28,9 +28,11 @@ class BluetoothChooserController : public ChooserController {
   ~BluetoothChooserController() override;
 
   // ChooserController:
+  bool ShouldShowIconBeforeText() const override;
   base::string16 GetNoOptionsText() const override;
   base::string16 GetOkButtonLabel() const override;
   size_t NumOptions() const override;
+  int GetSignalStrengthLevel(size_t index) const override;
   base::string16 GetOption(size_t index) const override;
   void RefreshOptions() override;
   base::string16 GetStatus() const override;
@@ -53,7 +55,7 @@ class BluetoothChooserController : public ChooserController {
                          const base::string16& device_name,
                          bool is_gatt_connected,
                          bool is_paired,
-                         const int8_t* rssi);
+                         int signal_strength_level);

[Jeffrey Yasskin, 2016/08/20 00:03:29]

Say what the bounds on the signal strength are (-1 to 4 inclusive, right?).

[juncai, 2016/08/20 01:17:02]

Done.

 
   // Tells the chooser that a device is no longer available.
   void RemoveDevice(const std::string& device_id);
@@ -63,11 +65,16 @@ class BluetoothChooserController : public ChooserController {
   void ResetEventHandler();
 
  private:
+  struct BluetoothDeviceInfo {
+    std::string id;
+    int signal_strength_level;
+  };
+
   // Clears |device_names_and_ids_| and |device_name_counts_|. Called when
   // Bluetooth adapter is turned on or off, or when re-scan happens.
   void ClearAllDevices();
 
-  std::vector<std::string> device_ids_;
+  std::vector<BluetoothDeviceInfo> devices_;
   std::unordered_map<std::string, base::string16> device_id_to_name_map_;
   // Maps from device name to number of devices with that name.
   std::unordered_map<base::string16, int> device_name_counts_;