[NOT FOR REVIEW] ash: Add some implementation for the window management extension API.

chrome/browser/extensions/api/wm/wm_utils.h

Index: chrome/browser/extensions/api/wm/wm_utils.h
diff --git a/chrome/browser/extensions/api/wm/wm_utils.h b/chrome/browser/extensions/api/wm/wm_utils.h
new file mode 100644
index 0000000000000000000000000000000000000000..f3e115f2aa035fa4797ac05aec2956357e0fc47f
--- /dev/null
+++ b/chrome/browser/extensions/api/wm/wm_utils.h
@@ -0,0 +1,64 @@
+// Copyright (c) 2012 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_EXTENSIONS_API_WM_WM_UTILS_H_
+#define CHROME_BROWSER_EXTENSIONS_API_WM_WM_UTILS_H_
+
+#include <list>
+#include <map>
+#include <vector>
+
+#include "base/memory/singleton.h"
+#include "ui/gfx/native_widget_types.h"
+
+namespace extensions {
+namespace api {
+
+namespace experimental_wm {
+class WmWindow;
+}
+
+namespace wm {
+
+// WindowIdTracker manages the extension-visible IDs of the native Windows.
+class WindowIdTracker {
+ private:
+  WindowIdTracker();
+  ~WindowIdTracker();
+
+ public:
+  static WindowIdTracker* GetInstance();
+
+  // Returns the extension-visible ID for the window. This generates a new
+  // unique ID for the window if it didn't have one already (or if it was
+  // invalidated by calling UntrackWindow().
+  int GetWindowExtensionId(gfx::NativeWindow window);
+
+  // Invalidates the extension-visible ID for the window.
+  void UntrackWindow(gfx::NativeWindow window);
+
+ private:
+  // Requirement for Signleton
+  friend struct DefaultSingletonTraits<WindowIdTracker>;
+
+  std::list<gfx::NativeWindow> activation_order_;
+  std::list<gfx::NativeWindow> creation_order_;
+  std::map<int, gfx::NativeWindow> reverse_lookup_;
+  std::map<gfx::NativeWindow, int> lookup_;
+  int next_window_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(WindowIdTracker);
+};
+
+namespace utils {
+
+void NativeWindowToExtensionWindow(gfx::NativeWindow window,
+                                   experimental_wm::WmWindow* extension_window);
+
+}  // namespace utils
+}  // namespace wm
+}  // namespace api
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_WM_WM_UTILS_H_