[Extensions] Make chrome://extensions use developerPrivate for unpacked loading

chrome/browser/extensions/api/developer_private/developer_private_api.h

 // Copyright (c) 2012 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_API_DEVELOPER_PRIVATE_DEVELOPER_PRIVATE_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_DEVELOPER_PRIVATE_DEVELOPER_PRIVATE_API_H_
 
 #include <set>
 
 #include "base/files/file.h"
@@ skipping 294 matching lines @@
                   const ui::SelectFileDialog::FileTypeInfo& info,
                   int file_type_index);
 };
 
 
 class DeveloperPrivateLoadUnpackedFunction
     : public DeveloperPrivateChooseEntryFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("developerPrivate.loadUnpacked",
                              DEVELOPERPRIVATE_LOADUNPACKED);
+  DeveloperPrivateLoadUnpackedFunction();
 
  protected:
   ~DeveloperPrivateLoadUnpackedFunction() override;
   ResponseAction Run() override;
 
   // EntryPickerClient:
   void FileSelected(const base::FilePath& path) override;
   void FileSelectionCanceled() override;
+
+  // Callback for the UnpackedLoader.
+  void OnLoadComplete(const Extension* extension,
+                      const base::FilePath& file_path,
+                      const std::string& error);
+
+ private:
+  // Whether or not we should fail quietly in the event of a load error.
+  bool fail_quietly_;
 };
 
 class DeveloperPrivateChoosePathFunction
     : public DeveloperPrivateChooseEntryFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("developerPrivate.choosePath",
                              DEVELOPERPRIVATE_CHOOSEPATH);
 
  protected:
   ~DeveloperPrivateChoosePathFunction() override;
@@ skipping 130 matching lines @@
 
   // ExtensionFunction:
   bool RunAsync() override;
 };
 
 }  // namespace api
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_DEVELOPER_PRIVATE_DEVELOPER_PRIVATE_API_H_