Check Extension in extension_error_ui_util

chrome/browser/ui/webui/extensions/extension_error_ui_util.cc

 // 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.
 
 #include "chrome/browser/ui/webui/extensions/extension_error_ui_util.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/location.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/values.h"
 #include "chrome/browser/devtools/devtools_window.h"
-#include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 #include "extensions/browser/extension_error.h"
-#include "extensions/browser/extension_system.h"
+#include "extensions/browser/extension_registry.h"
 #include "extensions/browser/file_highlighter.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension.h"
 
 namespace extensions {
 namespace error_ui_util {
 
 namespace {
 
 // Keys for objects passed to and from extension error UI.
@@ skipping 35 matching lines @@
   base::FilePath::StringType path_suffix_string;
   base::string16 error_message;
 
   if (!args->GetString(kPathSuffixKey, &path_suffix_string) ||
       !args->GetString(ExtensionError::kExtensionIdKey, &extension_id) ||
       !args->GetString(ExtensionError::kMessageKey, &error_message)) {
     NOTREACHED();
     return;
   }
 
-  ExtensionService* extension_service =
-      ExtensionSystem::Get(profile)->extension_service();
-  if (!extension_service)
+  const Extension* extension =
+      ExtensionRegistry::Get(profile)->GetExtensionById(
+          extension_id, ExtensionRegistry::EVERYTHING);
+
+  if (!extension)
     return;

[Finnur, 2014/04/10 12:24:02]

Looks like it would fix the crash, but do we have a good understanding as to why
we end up in this situation?  

[Devlin, 2014/04/10 16:21:08]

My suspicion is that, since we really only enter this code path when an
extension encounters an error, the extension may have crashed, and entered the
terminated state (which is the only state which
ExtensionService::GetExtensionById() doesn't check).  I think that subbing in
ExtensionRegistry::GetExtensionById(EVERYTHING) will solve this, but, on the
off-chance it doesn't, we should fail gracefully (at least in release builds). 
Added a NOTREACHED() so we can tell in Debug builds if this truly fixed the
problem.

 
-  const Extension* extension = extension_service->GetExtensionById(
-      extension_id, true /* include disabled */);
-
   // Under no circumstances should we ever need to reference a file outside of
   // the extension's directory. If it tries to, abort.
   base::FilePath path_suffix(path_suffix_string);
   if (path_suffix.ReferencesParent())
     return;
 
   base::FilePath path = extension->path().Append(path_suffix);
 
   // Setting the title and the error message is the same for all file types.
   scoped_ptr<base::DictionaryValue> results(new base::DictionaryValue);
@@ skipping 86 matching lines @@
   if (!browser || !browser->is_type_tabbed())
     return;
 
   TabStripModel* tab_strip = browser->tab_strip_model();
   tab_strip->ActivateTabAt(tab_strip->GetIndexOfWebContents(web_contents),
                            false);  // Not through direct user gesture.
 }
 
 }  // namespace error_ui_util
 }  // namespace extensions