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

chrome/browser/chooser_controller/chooser_controller.h

Index: chrome/browser/chooser_controller/chooser_controller.h
diff --git a/chrome/browser/chooser_controller/chooser_controller.h b/chrome/browser/chooser_controller/chooser_controller.h
index c5a3609b5377cd44fff62e24534b980e7b021967..47fcf8e1b2032758ac0ef8fa62e601d9b7754856 100644
--- a/chrome/browser/chooser_controller/chooser_controller.h
+++ b/chrome/browser/chooser_controller/chooser_controller.h
@@ -59,6 +59,9 @@ class ChooserController {
   // Returns the text to be displayed in the chooser title.
   base::string16 GetTitle() const;
 
+  // Returns if the chooser needs to show an icon before the text.
+  virtual bool HasIconBeforeText() const = 0;

[msw, 2016/08/12 23:08:48]

optional nit: ShouldShowIconBeforeText

[juncai, 2016/08/15 21:53:19]

Done.

+
   // Returns the text to be displayed in the chooser when there are no options.
   virtual base::string16 GetNoOptionsText() const = 0;
 
@@ -70,6 +73,11 @@ class ChooserController {
   // chooser so that users can grant permission.
   virtual size_t NumOptions() const = 0;
 
+  // The |index|th device signal strength level (non-negative), which is used to

[msw, 2016/08/12 23:08:48]

nit: "The signal strength level (non-negative) of the device at |index|,
which"...

[juncai, 2016/08/15 21:53:19]

Done.

+  // retrieve corresponding icon to be displayed before the text. Return -1 for

[msw, 2016/08/12 23:08:48]

nit: "retrieve the corresponding", "Returns -1 if no icon should be shown."

[juncai, 2016/08/15 21:53:19]

Done.

+  // not displaying any icon.
+  virtual int GetSignalStrengthLevel(size_t index) const = 0;
+
   // The |index|th option string which is listed in the chooser.
   virtual base::string16 GetOption(size_t index) const = 0;