Introduce apps API target in //apps and move app.runtime API into it

apps/browser/file_handler_util.cc

Index: apps/browser/file_handler_util.cc
diff --git a/apps/browser/file_handler_util.cc b/apps/browser/file_handler_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..073760aa12552d321ebbe9670c85d370c8817571
--- /dev/null
+++ b/apps/browser/file_handler_util.cc
@@ -0,0 +1,15 @@
+// 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.
+
+#include "apps/browser/file_handler_util.h"
+
+namespace apps {
+namespace file_handler_util {
+
+GrantedFileEntry::GrantedFileEntry() {}
+
+GrantedFileEntry::~GrantedFileEntry() {}
+
+}  // namespace file_handler_util
+}  // namespace apps