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 9fe26d0cb45098db6664b3d143e7055652a46142..6a58361c614650682ac071d4dbbd71f466b32407 100644
--- a/chrome/browser/chooser_controller/chooser_controller.h
+++ b/chrome/browser/chooser_controller/chooser_controller.h
@@ -62,6 +62,10 @@ 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.
+  // For WebBluetooth, it is a signal strength icon.
+  virtual bool ShouldShowIconBeforeText() const;
+
   // Returns the text to be displayed in the chooser when there are no options.
   virtual base::string16 GetNoOptionsText() const = 0;
 
@@ -73,6 +77,11 @@ class ChooserController {
   // chooser so that users can grant permission.
   virtual size_t NumOptions() const = 0;
 
+  // The signal strength level (0-4 inclusive) of the device at |index|, which
+  // is used to retrieve the corresponding icon to be displayed before the
+  // text. Returns -1 if no icon should be shown.
+  virtual int GetSignalStrengthLevel(size_t index) const;
+
   // The |index|th option string which is listed in the chooser.
   virtual base::string16 GetOption(size_t index) const = 0;