Refactor loading out of ExtensionService.

chrome/browser/extensions/component_loader.h

+// Copyright (c) 2011 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 CHROME_BROWSER_EXTENSIONS_COMPONENT_LOADER_H_
+#define CHROME_BROWSER_EXTENSIONS_COMPONENT_LOADER_H_
+#pragma once
+
+#include <string>
+
+#include "base/file_path.h"
+
+class Extension;
+class ExtensionService;
+
+namespace extensions {
+
+// For registering, loading, and unloading component extensions.
+class ComponentLoader {
+ public:
+  explicit ComponentLoader(ExtensionService* extension_service);
+  virtual ~ComponentLoader();
+
+  // Loads any registered component extensions.
+  void LoadAll();
+
+  // Loads and registers a component extension. If ExtensionService has been
+  // initialized, the extension is loaded; otherwise, the load is deferred
+  // until LoadAll is called.
+  const Extension* Add(const std::string& manifest,
+                       const FilePath& root_directory);
+
+  // Unloads a component extension and removes it from the list of component
+  // extensions to be loaded.
+  void Remove(const std::string& manifest_str);
+
+  // Adds the default component extensions.
+  //
+  // Component extension manifests must contain a 'key' property with a unique
+  // public key, serialized in base64. You can create a suitable value with the
+  // following commands on a unixy system:
+  //
+  //   ssh-keygen -t rsa -b 1024 -N '' -f /tmp/key.pem
+  //   openssl rsa -pubout -outform DER < /tmp/key.pem 2>/dev/null | base64 -w 0
+  void AddDefaultComponentExtensions();
+
+ private:
+  // Information about a registered component extension.
+  struct ComponentExtensionInfo {
+    ComponentExtensionInfo(const std::string& manifest,
+                           const FilePath& root_directory)
+        : manifest(manifest),
+          root_directory(root_directory) {
+    }
+
+    bool Equals(const ComponentExtensionInfo& other) const;
+
+    // The extension's manifest. This is required for component extensions so
+    // that ExtensionService doesn't need to go to disk to load them.
+    std::string manifest;
+
+    // Directory where the extension is stored.
+    FilePath root_directory;
+  };
+
+  // Loads a registered component extension.
+  const Extension* Load(const ComponentExtensionInfo& info);
+
+  // Registers an extension to be loaded as a component extension.
+  void Register(const ComponentExtensionInfo& info) {
+    component_extensions_.push_back(info);
+  }
+
+  // List of registered component extensions (see Extension::Location).
+  typedef std::vector<ComponentExtensionInfo> RegisteredComponentExtensions;
+  RegisteredComponentExtensions component_extensions_;
+
+  ExtensionService* extension_service_;
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_COMPONENT_LOADER_H_