Introduce lock screen app context to extension features

extensions/browser/extensions_browser_client.h

Index: extensions/browser/extensions_browser_client.h
diff --git a/extensions/browser/extensions_browser_client.h b/extensions/browser/extensions_browser_client.h
index 5ddbde70f6bb7e88071e2e6b119ebeed6427e785..92776e735dd680d5d8afcc9db6737c2cc81187ec 100644
--- a/extensions/browser/extensions_browser_client.h
+++ b/extensions/browser/extensions_browser_client.h
@@ -263,6 +263,9 @@ class ExtensionsBrowserClient {
   // Returns a delegate that provides kiosk mode functionality.
   virtual KioskDelegate* GetKioskDelegate() = 0;
 
+  // Whether the browser context is associted with Chrome OS lock screen.
+  virtual bool IsLockScreenContext(content::BrowserContext* context) = 0;
+
   // Returns the single instance of |this|.
   static ExtensionsBrowserClient* Get();