Aura/ash split: Don't use X11 window borders.

ui/base/x/x11_atom_cache.h

+// 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 UI_BASE_X_X11_ATOM_CACHE_H_
+#define UI_BASE_X_X11_ATOM_CACHE_H_
+
+#include "base/basictypes.h"
+#include "base/memory/singleton.h"
+#include "ui/base/ui_export.h"
+
+#include <X11/Xlib.h>
+
+#include <map>
+
+// Get rid of a macro from Xlib.h that conflicts with Aura's RootWindow class.
+#undef RootWindow
+
+namespace ui {
+
+// Names of cached atoms that we fetch during the constructor to minimize
+// round trips to the X11 server.
+enum AtomName {
+  ATOM_WM_DELETE_WINDOW = 0,
+  ATOM__NET_WM_MOVERESIZE,
+  ATOM__NET_WM_PING,
+  ATOM__NET_WM_PID,
+  ATOM_WM_S0,
+  ATOM__MOTIF_WM_HINTS,
+
+  ATOM_COUNT
+};
+
+// Pre-caches all Atoms on first use to minimize roundtrips to the X11

[sadrul, 2012/05/15 22:08:12]

This doc may be confusing with ui::GetAtom (in ui/base/x/x11_util.h). Perhaps
clarify that the cache is for the atoms listed in AtomName.

+// server. Assumes that we only have a single X11 display,
+// base::MessagePumpX::GetDefaultXDisplay().
+class UI_EXPORT X11AtomCache {
+ public:
+  static X11AtomCache* GetInstance();
+
+  // Returns the pre-interned Atom by enum instead of string.
+  ::Atom GetAtom(AtomName name) const;
+
+ private:
+  friend struct DefaultSingletonTraits<X11AtomCache>;
+
+  // Constructor performs all interning
+  X11AtomCache();
+  ~X11AtomCache();
+
+  std::map<AtomName, ::Atom> cached_atoms_;
+
+  DISALLOW_COPY_AND_ASSIGN(X11AtomCache);
+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_X_ATOM_CACHE_H_