Add setBounds method and browsertest for get/set bounds to app window API

chrome/common/extensions/api/app_current_window_internal.idl

 // 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.
 
 // This is used by the app window API internally to pass through messages to
 // the shell window.
 [internal, nodoc] namespace app.currentWindowInternal {
+
+  // TODO(asargent) - We need to add support for referencing types in
+  // other namespaces (crbug.com/158654). For now just duplicate this
+  // dictionary from app.window.
+  dictionary Bounds {
+    long? left;
+    long? top;
+    long? width;
+    long? height;
+  };
+
+
   interface Functions {
     static void focus();
     static void minimize();
     static void maximize();
     static void restore();
     static void drawAttention();
     static void clearAttention();
     static void show();
     static void hide();
+    static void setBounds(Bounds bounds);
   };
 };