Introduce lock screen app manager interface

chrome/browser/chromeos/note_taking_helper.h

Index: chrome/browser/chromeos/note_taking_helper.h
diff --git a/chrome/browser/chromeos/note_taking_helper.h b/chrome/browser/chromeos/note_taking_helper.h
index 2113d906a82d54a78168ddc61fae68ae0f3f693a..691b7efd3bb9812759893a558f107b52f7efed26 100644
--- a/chrome/browser/chromeos/note_taking_helper.h
+++ b/chrome/browser/chromeos/note_taking_helper.h
@@ -158,6 +158,11 @@ class NoteTakingHelper : public arc::ArcIntentHelperObserver,
   // Returns a list of available note-taking apps.
   std::vector<NoteTakingAppInfo> GetAvailableApps(Profile* profile);
 
+  // Returns the preferred app info, if the preferred app exists and is a Chrome
+  // app.
+  std::unique_ptr<NoteTakingAppInfo> GetPreferredChromeAppInfo(
+      Profile* profile);
+
   // Sets the preferred note-taking app. |app_id| is a value from a
   // NoteTakingAppInfo object.
   void SetPreferredApp(Profile* profile, const std::string& app_id);