Move sandboxed_unpacker.{h,cc} from chrome/ to extensions/

chrome/utility/extensions/extensions_handler.h

Index: chrome/utility/extensions/extensions_handler.h
diff --git a/chrome/utility/extensions/extensions_handler.h b/chrome/utility/extensions/extensions_handler.h
index 3a001b1561019a42e6ec0cb8b3ff2ee0975775e0..aeae76962a212f841dd817943b0dc43de3928ee6 100644
--- a/chrome/utility/extensions/extensions_handler.h
+++ b/chrome/utility/extensions/extensions_handler.h
@@ -29,16 +29,12 @@ class ExtensionsHandler : public UtilityMessageHandler {
   ~ExtensionsHandler() override;
 
   static void PreSandboxStartup();
-  static void UtilityThreadStarted();
 
   // UtilityMessageHandler:
   bool OnMessageReceived(const IPC::Message& message) override;
 
  private:
   // IPC message handlers.
-  void OnUnpackExtension(const base::FilePath& extension_path,
-                         const std::string& extension_id,
-                         int location, int creation_flags);
   void OnUnzipToDir(const base::FilePath& zip_path, const base::FilePath& dir);
   void OnDecodeImageBase64(const std::string& encoded_data);
   void OnCheckMediaFile(int64 milliseconds_of_decoding,