[Refactor] Move code for painting the window header for browser windows out of ash

ash/wm/header_metrics.h

+// Copyright 2014 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 ASH_WM_HEADER_METRICS_H_
+#define ASH_WM_HEADER_METRICS_H_
+
+#include "ash/ash_export.h"
+#include "base/macros.h"
+
+namespace gfx {
+class FontList;
+class Rect;
+}
+
+namespace views {
+class View;
+}
+
+namespace ash {
+
+// Static-only helper class for painting the window header.
+class ASH_EXPORT HeaderMetrics {
+ public:
+  // Returns the radius of the header's corners when the window is restored.
+  static int GetTopCornerRadiusWhenRestored();
+
+  // Returns the distance between the left edge of the window and the header
+  // icon.
+  static int GetIconXOffset();
+
+  // Returns the size of the header icon.
+  static int GetIconSize();
+
+  // Returns the bounds for the header's title given the header icon, the
+  // caption button container and the font used.
+  // |window_icon| should  NULL if the header does not use an icon.

[James Cook, 2014/03/10 17:32:30]

nit: "should be"

+  static gfx::Rect GetTitleBounds(const views::View* icon,

[James Cook, 2014/03/10 17:32:30]

either |window_icon| or change comment above

+                                  const views::View* caption_button_container,
+                                  const gfx::FontList& title_font_list);
+
+  // Returns the amount that the frame background is inset from the left edge of
+  // the window.
+  static int GetThemeBackgroundXInset();
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(HeaderMetrics);
+};
+
+}  // namespace ash
+
+#endif  // ASH_WM_HEADER_METRICS_H_