[MD Extensions] Respond with a load error when loading unpacked fails

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

Index: chrome/browser/extensions/api/developer_private/developer_private_api.h
diff --git a/chrome/browser/extensions/api/developer_private/developer_private_api.h b/chrome/browser/extensions/api/developer_private/developer_private_api.h
index 607e3029d07975be4212803d74caa8cfccea0998..0a5f59554399462ff19d3d4643e167e573f8b391 100644
--- a/chrome/browser/extensions/api/developer_private/developer_private_api.h
+++ b/chrome/browser/extensions/api/developer_private/developer_private_api.h
@@ -395,8 +395,16 @@ class DeveloperPrivateLoadUnpackedFunction
                       const std::string& error);
 
  private:
+  void OnGotManifestError(const base::FilePath& file_path,
+                          const std::string& error,
+                          size_t line_number,
+                          const std::string& manifest);
+
   // Whether or not we should fail quietly in the event of a load error.
-  bool fail_quietly_;
+  bool fail_quietly_ = false;
+
+  // Whether we populate a load error on failure.

[lazyboy, 2017/03/22 21:38:46]

nit: populate developer_private::LoadError on failure, opposed to lastError.

[Devlin, 2017/03/23 01:30:59]

Done.

+  bool populate_error_ = false;
 };
 
 class DeveloperPrivateChoosePathFunction