Move most of the component updater artifacts to update_client.

components/update_client/update_checker.h

Index: components/update_client/update_checker.h
diff --git a/components/update_client/update_checker.h b/components/update_client/update_checker.h
new file mode 100644
index 0000000000000000000000000000000000000000..1ac642628267597ff7d987dc5c62e77cc999b9cb
--- /dev/null
+++ b/components/update_client/update_checker.h
@@ -0,0 +1,57 @@
+// 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.
+
+#ifndef COMPONENTS_UPDATE_CLIENT_UPDATE_CHECKER_H_
+#define COMPONENTS_UPDATE_CLIENT_UPDATE_CHECKER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "components/update_client/update_response.h"
+#include "url/gurl.h"
+
+class GURL;
+
+namespace net {
+class URLRequestContextGetter;
+}
+
+namespace update_client {
+
+class Configurator;
+struct CrxUpdateItem;
+
+class UpdateChecker {
+ public:
+  typedef base::Callback<void(const GURL& original_url,
+                              int error,
+                              const std::string& error_message,
+                              const UpdateResponse::Results& results)>
+      UpdateCheckCallback;
+
+  virtual ~UpdateChecker() {}
+
+  // Initiates an update check for the |items_to_check|. |additional_attributes|
+  // provides a way to customize the <request> element. This value is inserted
+  // as-is, therefore it must be well-formed as an XML attribute string.
+  virtual bool CheckForUpdates(
+      const std::vector<CrxUpdateItem*>& items_to_check,
+      const std::string& additional_attributes,
+      const UpdateCheckCallback& update_check_callback) = 0;
+
+  static scoped_ptr<UpdateChecker> Create(const Configurator& config);
+
+ protected:
+  UpdateChecker() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(UpdateChecker);
+};
+
+}  // namespace update_client
+
+#endif  // COMPONENTS_UPDATE_CLIENT_UPDATE_CHECKER_H_