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

chrome/browser/ui/webui/extensions/extension_loader_handler.h

 // Copyright 2014 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_UI_WEBUI_EXTENSIONS_EXTENSION_LOADER_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_EXTENSIONS_EXTENSION_LOADER_HANDLER_H_
 
 #include <stddef.h>
 
 #include <memory>
 #include <string>
 #include <vector>
 
+#include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/extension_error_reporter.h"
 #include "content/public/browser/reload_type.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_ui_message_handler.h"
 
 namespace content {
 class WebUIDataSource;
 }
 
 class Profile;
 
 namespace extensions {
 
 class Extension;
 
 // The handler page for the Extension Commands UI overlay.
 class ExtensionLoaderHandler : public content::WebUIMessageHandler,
                                public ExtensionErrorReporter::Observer,
                                public content::WebContentsObserver {
  public:
+  using GetManifestErrorCallback =
+      base::Callback<void(const base::FilePath& file_path,
+                          const std::string& error,
+                          size_t line_number,
+                          const std::string& manifest)>;
+
   explicit ExtensionLoaderHandler(Profile* profile);
   ~ExtensionLoaderHandler() override;
 
   // Fetches the localized values for the page and deposits them into |source|.
   void GetLocalizedValues(content::WebUIDataSource* source);
 
   // WebUIMessageHandler implementation.
   void RegisterMessages() override;
 
+  // TODO(devlin): Move this out of here into developerPrivate.

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

optional nit: "Move this to developerPrivate."

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

Done.

+  static void GetManifestError(const std::string& error,
+                               const base::FilePath& extension_path,
+                               const GetManifestErrorCallback& callback);
+
  private:
   // Handle the 'extensionLoaderRetry' message.
   void HandleRetry(const base::ListValue* args);
 
   // Handle the 'extensionLoaderIgnoreFailure' message.
   void HandleIgnoreFailure(const base::ListValue* args);
 
   // Handle the 'extensionLoaderDisplayFailures' message.
   void HandleDisplayFailures(const base::ListValue* args);
 
@@ skipping 40 matching lines @@
 
   // Weak pointer factory for posting background tasks.
   base::WeakPtrFactory<ExtensionLoaderHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionLoaderHandler);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_UI_WEBUI_EXTENSIONS_EXTENSION_LOADER_HANDLER_H_