Move OmahaQueryParams to a component and add a delegate interface.

apps/shell/browser/shell_omaha_query_params_delegate.cc

+// 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/shell/browser/shell_omaha_query_params_delegate.h"
+
+namespace extensions {
+
+ShellOmahaQueryParamsDelegate::ShellOmahaQueryParamsDelegate() {
+}
+
+ShellOmahaQueryParamsDelegate::~ShellOmahaQueryParamsDelegate() {
+}
+
+std::string ShellOmahaQueryParamsDelegate::GetExtraParams() {
+  // This version number is high enough to be supported by Omaha
+  // (below 31 is unsupported), but it's fake enough to be obviously
+  // not a Chrome release.
+  return "&prodversion=38.1234.5678.9";
+}
+
+}  // namespace extensions