Move ViewHostMsg_CreateWindow to mojom

ui/base/window_open_disposition.mojom

Index: ui/base/window_open_disposition.mojom
diff --git a/ui/base/window_open_disposition.mojom b/ui/base/window_open_disposition.mojom
new file mode 100644
index 0000000000000000000000000000000000000000..ba5c876114974b321e4b5fadd39c341014586d40
--- /dev/null
+++ b/ui/base/window_open_disposition.mojom
@@ -0,0 +1,24 @@
+// Copyright 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.
+
+module ui.mojom;
+
+// TODO(rockot/ben): This definitely seems like the wrong layer for a
+// "window open disposition" concept. It's here to support existing uses of
+// ui::WindowOpenDisposition.
+//
+// This maps to WindowOpenDisposition in //ui/base/window_open_disposition.h.
+enum WindowOpenDisposition {
+  UNKNOWN,
+  CURRENT_TAB,
+  // Indicates that only one tab with the url should exist in the same window.
+  SINGLETON_TAB,
+  NEW_FOREGROUND_TAB,
+  NEW_BACKGROUND_TAB,
+  NEW_POPUP,
+  NEW_WINDOW,
+  SAVE_TO_DISK,
+  OFF_THE_RECORD,
+  IGNORE_ACTION,
+};