Add help link when Bluetooth adapter is off for WebBluetooth chooser on Mac

chrome/browser/ui/cocoa/chooser_content_view_cocoa.h

Index: chrome/browser/ui/cocoa/chooser_content_view_cocoa.h
diff --git a/chrome/browser/ui/cocoa/chooser_content_view_cocoa.h b/chrome/browser/ui/cocoa/chooser_content_view_cocoa.h
index 34dff6fe75534e0cf53f36ce0ec949fc4ce2a446..564657317b06b917c88cd937906f82f262a9e27b 100644
--- a/chrome/browser/ui/cocoa/chooser_content_view_cocoa.h
+++ b/chrome/browser/ui/cocoa/chooser_content_view_cocoa.h
@@ -19,6 +19,7 @@ class ChooserController;
 @interface ChooserContentViewCocoa : NSView {
  @private
   base::scoped_nsobject<NSTextField> titleView_;
+  base::scoped_nsobject<NSButton> adapterOffHelpButton_;
   base::scoped_nsobject<NSScrollView> scrollView_;
   base::scoped_nsobject<NSTableColumn> tableColumn_;
   base::scoped_nsobject<NSTableView> tableView_;
@@ -110,6 +111,9 @@ class ChooserController;
 // Updates the origin and size of the view.
 - (void)updateView;
 
+// Gets the adapter off help button.
+- (NSButton*)adapterOffHelpButton;
+
 // Gets the table view for the chooser.
 - (NSTableView*)tableView;
 
@@ -149,6 +153,9 @@ class ChooserController;
 // Called when the chooser is closed.
 - (void)close;
 
+// Called when the adapter off help button is pressed.
+- (void)onAdapterOffHelp:(id)sender;
+
 // Called when "Re-scan" button is pressed.
 - (void)onRescan:(id)sender;