Decouple IsMetroProcess() calls, introducing IsSingleWindowMetroMode().

win8/util/win8_util.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 WIN8_UTIL_WIN8_UTIL_H_
+#define WIN8_UTIL_WIN8_UTIL_H_
+
+namespace win8 {
+
+// Returns true if this process is running in fullscreen Metro mode on Win8+.
+// Callers should always prefer this method to base::win::IsMetroProcess() for
+// UI properties dependent on the single window mode as this method is also
+// aware of the Ash environment in which multiple Chrome windows can live.
+bool IsSingleWindowMetroMode();
+
+}  // namespace win8
+
+#endif  // WIN8_UTIL_WIN8_UTIL_H_