Make ComponentInstaller refcounted.

components/update_client/update_client.h

 // Copyright 2015 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_CLIENT_H_
 #define COMPONENTS_UPDATE_CLIENT_UPDATE_CLIENT_H_
 
 #include <stdint.h>
 #include <string>
 #include <vector>
 
+#include "base/memory/ref_counted.h"
 #include "base/version.h"
 
 namespace base {
 class DictionaryValue;
 class FilePath;
 }
 
 namespace update_client {
 
 // Component specific installers must derive from this class and implement
 // OnUpdateError() and Install(). A valid instance of this class must be
 // given to ComponentUpdateService::RegisterComponent().
-class ComponentInstaller {
+class ComponentInstaller
+    : public base::RefCountedThreadSafe<ComponentInstaller> {
  public:
   // Called by the component updater on the main thread when there was a
   // problem unpacking or verifying the component. |error| is a non-zero
   // value which is only meaningful to the component updater.
   virtual void OnUpdateError(int error) = 0;
 
   // Called by the component updater when a component has been unpacked
   // and is ready to be installed. |manifest| contains the CRX manifest
   // json dictionary and |unpack_path| contains the temporary directory
   // with all the unpacked CRX files. This method may be called from
   // a thread other than the main thread.
   virtual bool Install(const base::DictionaryValue& manifest,
                        const base::FilePath& unpack_path) = 0;
 
   // Set |installed_file| to the full path to the installed |file|. |file| is
   // the filename of the file in this component's CRX. Returns false if this is
   // not possible (the file has been removed or modified, or its current
   // location is unknown). Otherwise, returns true.
   virtual bool GetInstalledFile(const std::string& file,
                                 base::FilePath* installed_file) = 0;
 
+ protected:
+  friend class base::RefCountedThreadSafe<ComponentInstaller>;
+
   virtual ~ComponentInstaller() {}
 };
 
 // Describes a particular component that can be installed or updated. This
 // structure is required to register a component with the component updater.
 // |pk_hash| is the SHA256 hash of the component's public key. If the component
 // is to be installed then version should be "0" or "0.0", else it should be
 // the current version. |fingerprint|, and |name| are optional.
 // |allow_background_download| specifies that the component can be background
 // downloaded in some cases. The default for this value is |true| and the value
 // can be overriden at the registration time. This is a temporary change until
 // the issue 340448 is resolved.
 struct CrxComponent {
   std::vector<uint8_t> pk_hash;
-  ComponentInstaller* installer;
+  scoped_refptr<ComponentInstaller> installer;
   Version version;
   std::string fingerprint;
   std::string name;
   bool allow_background_download;
   CrxComponent();
   ~CrxComponent();
 };
 
 }  // namespace update_client
 
 #endif  // COMPONENTS_UPDATE_CLIENT_UPDATE_CLIENT_H_