Improve UI for unpacked extensions failing to load

chrome/browser/extensions/unpacked_installer.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_UNPACKED_INSTALLER_H_
 #define CHROME_BROWSER_EXTENSIONS_UNPACKED_INSTALLER_H_
 
 #include <string>
 #include <vector>
 
+#include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/extensions/extension_installer.h"
 
 class ExtensionService;
 
 namespace extensions {
 
 class Extension;
 class RequirementsChecker;
 
 // Installs and loads an unpacked extension. Because internal state needs to be
 // held about the instalation process, only one call to Load*() should be made
 // per UnpackedInstaller.
 // TODO(erikkay): It might be useful to be able to load a packed extension
 // (presumably into memory) without installing it.
 class UnpackedInstaller
     : public base::RefCountedThreadSafe<UnpackedInstaller> {
  public:
+  typedef base::Callback<void(const base::FilePath&, const std::string&)>
+      OnFailureCallback;
+
   static scoped_refptr<UnpackedInstaller> Create(
       ExtensionService* extension_service);
 
   // Loads the extension from the directory |extension_path|, which is
   // the top directory of a specific extension where its manifest file lives.
   // Errors are reported through ExtensionErrorReporter. On success,
   // ExtensionService::AddExtension() is called.
   void Load(const base::FilePath& extension_path);
 
   // Loads the extension from the directory |extension_path|;
@@ skipping 12 matching lines @@
 
   // Allows overriding of whether modern manifest versions are required;
   // intended for testing.
   bool require_modern_manifest_version() const {
     return require_modern_manifest_version_;
   }
   void set_require_modern_manifest_version(bool val) {
     require_modern_manifest_version_ = val;
   }
 
+  void set_on_failure_callback(const OnFailureCallback& callback) {
+    on_failure_callback_ = callback;
+  }
+
  private:
   friend class base::RefCountedThreadSafe<UnpackedInstaller>;
 
   explicit UnpackedInstaller(ExtensionService* extension_service);
   virtual ~UnpackedInstaller();
 
   // Must be called from the UI thread.
   void ShowInstallPrompt();
 
   // Calls CheckRequirements.
@@ skipping 36 matching lines @@
   base::FilePath extension_path_;
 
   // If true and the extension contains plugins, we prompt the user before
   // loading.
   bool prompt_for_plugins_;
 
   // Whether to require the extension installed to have a modern manifest
   // version.
   bool require_modern_manifest_version_;
 
+  // An optional callback to set in order to be notified of failure.
+  OnFailureCallback on_failure_callback_;
+
   // Gives access to common methods and data of an extension installer.
   ExtensionInstaller installer_;
 
   DISALLOW_COPY_AND_ASSIGN(UnpackedInstaller);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_UNPACKED_INSTALLER_H_