Pull CrxInstaller out of ExtensionsService.

chrome/browser/extensions/sandboxed_extension_unpacker.h

 // Copyright (c) 2009 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_SANDBOXED_EXTENSION_UNPACKER_H_
 #define CHROME_BROWSER_EXTENSIONS_SANDBOXED_EXTENSION_UNPACKER_H_
 
 #include <string>
 
 #include "base/file_path.h"
 #include "base/ref_counted.h"
 #include "base/scoped_temp_dir.h"
 #include "base/values.h"
 #include "chrome/browser/utility_process_host.h"
 
 class Extension;
 class MessageLoop;
 class ResourceDispatcherHost;
 
-class SandboxedExtensionUnpackerClient {
+class SandboxedExtensionUnpackerClient
+    : public base::RefCountedThreadSafe<SandboxedExtensionUnpackerClient> {
  public:
+  virtual ~SandboxedExtensionUnpackerClient(){
+  }
+
   // temp_dir - A temporary directoy containing the results of the extension
   // unpacking. The client is responsible for deleting this directory.
   //
   // extension_root - The path to the extension root inside of temp_dir.
   //
   // extension - The extension that was unpacked. The client is responsible
   // for deleting this memory.
   virtual void OnUnpackSuccess(const FilePath& temp_dir,
                                const FilePath& extension_root,
                                Extension* extension) = 0;
   virtual void OnUnpackFailure(const std::string& error) = 0;
 };
 
 // SandboxedExtensionUnpacker unpacks extensions from the CRX format into a
 // directory. This is done in a sandboxed subprocess to protect the browser
 // process from parsing complex formats like JPEG or JSON from untrusted
 // sources.
 //
 // Unpacking an extension using this class makes minor changes to its source,
 // such as transcoding all images to PNG and rewriting the manifest JSON. As
 // such, it should not be used when the output is not intended to be given back
 // to the author.
 //
+//
+// Lifetime management:
+//
+// This class is ref-counted by each call it makes to itself on another thread,
+// and by UtilityProcessHost.
+//
+// Additionally, we hold a reference to our own client so that it lives at least
+// long enough to receive the result of unpacking.
+//
+//
 // NOTE: This class should only be used on the file thread.
-
-
 class SandboxedExtensionUnpacker : public UtilityProcessHost::Client {
  public:
   // The size of the magic character sequence at the beginning of each crx
   // file, in bytes. This should be a multiple of 4.
   static const size_t kExtensionHeaderMagicSize = 4;
 
   // This header is the first data at the beginning of an extension. Its
   // contents are purposely 32-bit aligned so that it can just be slurped into
   // a struct without manual parsing.
   struct ExtensionHeader {
@@ skipping 49 matching lines @@
   void OnUnpackExtensionSucceeded(const DictionaryValue& manifest);
   void OnUnpackExtensionFailed(const std::string& error_message);
   void OnProcessCrashed();
 
   void ReportFailure(const std::string& message);
   void ReportSuccess();
 
   FilePath crx_path_;
   MessageLoop* client_loop_;
   ResourceDispatcherHost* rdh_;
-  SandboxedExtensionUnpackerClient* client_;
+  scoped_refptr<SandboxedExtensionUnpackerClient> client_;
   ScopedTempDir temp_dir_;
   FilePath extension_root_;
   scoped_ptr<Extension> extension_;
   bool got_response_;
   std::string public_key_;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_SANDBOXED_EXTENSION_UNPACKER_H_