Add "open as window" menu item to NTP app menu.

chrome/browser/extensions/extension_prefs.cc

Index: chrome/browser/extensions/extension_prefs.cc
diff --git a/chrome/browser/extensions/extension_prefs.cc b/chrome/browser/extensions/extension_prefs.cc
index 57c5c9ba1427f06adde28d8a4b042800ca494958..09b7dd6fcd8dfa1a0e68489d33a74572ecd24679 100644
--- a/chrome/browser/extensions/extension_prefs.cc
+++ b/chrome/browser/extensions/extension_prefs.cc
@@ -456,12 +456,22 @@ void ExtensionPrefs::SetAllowFileAccess(const std::string& extension_id,
 ExtensionPrefs::LaunchType ExtensionPrefs::GetLaunchType(
     const std::string& extension_id) {
   int value;
-  if (ReadExtensionPrefInteger(extension_id, kPrefLaunchType, &value) && (
-      value == LAUNCH_PINNED ||
+  if (ReadExtensionPrefInteger(extension_id, kPrefLaunchType, &value) &&
+     (value == LAUNCH_PINNED ||
       value == LAUNCH_REGULAR ||
-      value == LAUNCH_FULLSCREEN)) {
+      value == LAUNCH_FULLSCREEN ||
+      value == LAUNCH_WINDOW)) {
+
+#if defined(OS_MACOSX)
+    // App windows are not yet supported on mac.  Pref sync could make
+    // the launch type LAUNCH_WINDOW, even if there is no UI to set it
+    // on mac.
+    if (value == LAUNCH_WINDOW)
+      return LAUNCH_REGULAR;
+#endif
     return static_cast<LaunchType>(value);
   }
+
   return LAUNCH_REGULAR;
 }