Improve WebstoreInstaller error handling.

chrome/browser/extensions/webstore_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_WEBSTORE_INSTALLER_H_
 #define CHROME_BROWSER_EXTENSIONS_WEBSTORE_INSTALLER_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
+#include "content/public/browser/download_id.h"
+#include "content/public/browser/download_item.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
+#include "net/base/net_errors.h"
 #include "googleurl/src/gurl.h"
 
 class FilePath;
 class Profile;
 
 namespace content {
 class NavigationController;
 }
 
 // Downloads and installs extensions from the web store.
 class WebstoreInstaller : public content::NotificationObserver,
+                          public content::DownloadItem::Observer,
                           public base::RefCounted<WebstoreInstaller> {
  public:
   enum Flag {
     FLAG_NONE = 0,
 
     // Inline installs trigger slightly different behavior (install source
     // is different, download referrers are the item's page in the gallery).
     FLAG_INLINE_INSTALL = 1 << 0
   };
 
   class Delegate {
    public:
     virtual void OnExtensionInstallSuccess(const std::string& id) = 0;
     virtual void OnExtensionInstallFailure(const std::string& id,
                                            const std::string& error) = 0;
   };
 
-
   // Creates a WebstoreInstaller for downloading and installing the extension
   // with the given |id| from the Chrome Web Store. If |delegate| is not NULL,
   // it will be notified when the install succeeds or fails. The installer will
   // use the specified |controller| to download the extension. Only one
   // WebstoreInstaller can use a specific controller at any given time.
   // Note: the delegate should stay alive until being called back.
   WebstoreInstaller(Profile* profile,
                     Delegate* delegate,
                     content::NavigationController* controller,
                     const std::string& id,
                     int flags);
   virtual ~WebstoreInstaller();
 
   // Starts downloading and installing the extension.
   void Start();
 
   // content::NotificationObserver
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
   // Instead of using the default download directory, use |directory| instead.
   // This does *not* transfer ownership of |directory|.
   static void SetDownloadDirectoryForTests(FilePath* directory);
 
  private:
+  // DownloadManager::DownloadUrl callback.
+  void OnDownloadStarted(content::DownloadId id, net::Error error);
+
+  // DownloadItem::Observer implementation:
+  virtual void OnDownloadUpdated(content::DownloadItem* download) OVERRIDE;
+  virtual void OnDownloadOpened(content::DownloadItem* download) OVERRIDE;
+
   // Starts downloading the extension to |file_path|.
   void StartDownload(const FilePath& file_path);
 
   // Reports an install |error| to the delegate for the given extension if this
   // managed its installation. This also removes the associated PendingInstall.
   void ReportFailure(const std::string& error);
 
   // Reports a successful install to the delegate for the given extension if
   // this managed its installation. This also removes the associated
   // PendingInstall.
   void ReportSuccess();
 
   content::NotificationRegistrar registrar_;
   Profile* profile_;
   Delegate* delegate_;
   content::NavigationController* controller_;
   std::string id_;
+  // The DownloadItem is owned by the DownloadManager and is valid from when
+  // OnDownloadStarted is called (with no error) until the DownloadItem
+  // transitions to state REMOVING.
+  content::DownloadItem* download_item_;
   int flags_;
   GURL download_url_;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_WEBSTORE_INSTALLER_H_