Enable WebUI ScreenLocker for aura by abstracting lock window.

chrome/browser/chromeos/login/lock_window.h

Index: chrome/browser/chromeos/login/lock_window.h
diff --git a/chrome/browser/chromeos/login/lock_window.h b/chrome/browser/chromeos/login/lock_window.h
new file mode 100644
index 0000000000000000000000000000000000000000..de4532af435cf7925fadc01ee2fdbd33bf3610a3
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+++ b/chrome/browser/chromeos/login/lock_window.h
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+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_CHROMEOS_LOGIN_LOCK_WINDOW_H_
+#define CHROME_BROWSER_CHROMEOS_LOGIN_LOCK_WINDOW_H_
+#pragma once
+
+class DOMView;
+
+namespace views {
+class Widget;
+}
+
+namespace chromeos {
+
+// This is the interface which lock windows used for the WebUI screen locker
+// implement.
+class LockWindow {
+ public:
+  // This class provides an interface for the lock window to notify an observer
+  // about its status.
+  class Observer {
+   public:
+    // This method will be called when the lock window has finished all
+    // initialization.
+    virtual void OnLockWindowReady() = 0;
+  };
+
+  LockWindow();
+
+  // Attempt to grab inputs on |dom_view|, the actual view displaying the lock
+  // screen DOM.
+  virtual void Grab(DOMView* dom_view) = 0;
+
+  // Returns the actual widget for the lock window.
+  virtual views::Widget* GetWidget() = 0;
+
+  // Sets the observer class which is notified on lock window events.
+  void set_observer(Observer* observer) {
+    observer_ = observer;
+  }
+
+  // Creates an instance of the platform specific lock window.
+  static LockWindow* Create();
+
+ protected:
+  // The observer's OnLockWindowReady method will be called when the lock
+  // window has finished all initialization.
+  Observer* observer_;
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_LOCK_WINDOW_H_