options: Fix async font fetching crash

chrome/browser/ui/webui/options/font_settings_handler.cc

 // 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.
 
 #include "chrome/browser/ui/webui/options/font_settings_handler.h"
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ skipping 46 matching lines @@
 
 const char kAdvancedFontSettingsExtensionId[] =
     "caclkomlalccbpcdllchkeecicepbmbm";
 
 }  // namespace
 
 
 namespace options {
 
 FontSettingsHandler::FontSettingsHandler()
-    : extension_registry_observer_(this) {
+    : extension_registry_observer_(this),
+      weak_ptr_factory_(this) {
 }
 
 FontSettingsHandler::~FontSettingsHandler() {
 }
 
 void FontSettingsHandler::GetLocalizedValues(
     base::DictionaryValue* localized_strings) {
   DCHECK(localized_strings);
 
   static OptionsStringResource resources[] = {
@@ skipping 105 matching lines @@
 void FontSettingsHandler::OnExtensionUnloaded(
     content::BrowserContext* browser_context,
     const extensions::Extension* extension,
     extensions::UnloadedExtensionInfo::Reason reason) {
   NotifyAdvancedFontSettingsAvailability();
 }
 
 void FontSettingsHandler::HandleFetchFontsData(const base::ListValue* args) {
   content::GetFontListAsync(
       base::Bind(&FontSettingsHandler::FontsListHasLoaded,
-                 base::Unretained(this)));
+                 weak_ptr_factory_.GetWeakPtr()));
 }
 
 void FontSettingsHandler::FontsListHasLoaded(
     scoped_ptr<base::ListValue> list) {
   // Selects the directionality for the fonts in the given list.
   for (size_t i = 0; i < list->GetSize(); i++) {
     base::ListValue* font;
     bool has_font = list->GetList(i, &font);
     DCHECK(has_font);
     base::string16 value;
@@ skipping 108 matching lines @@
       chrome::FindBrowserWithWebContents(web_ui()->GetWebContents()));
 }
 
 void FontSettingsHandler::OnWebKitDefaultFontSizeChanged() {
   SetUpStandardFontSample();
   SetUpSerifFontSample();
   SetUpSansSerifFontSample();
 }
 
 }  // namespace options