Allow overriding WebUIFactory when test flag is set.

chrome/browser/ui/webui/chrome_web_ui_factory.cc

 // Copyright (c) 2011 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/chrome_web_ui_factory.h"
 
 #include "base/command_line.h"
 #include "chrome/browser/about_flags.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_web_ui.h"
 #include "chrome/browser/extensions/extensions_ui.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/webui/bookmarks_ui.h"
 #include "chrome/browser/ui/webui/bug_report_ui.h"
 #include "chrome/browser/ui/webui/constrained_html_ui.h"
 #include "chrome/browser/ui/webui/crashes_ui.h"
 #include "chrome/browser/ui/webui/devtools_ui.h"
 #include "chrome/browser/ui/webui/downloads_ui.h"
 #include "chrome/browser/ui/webui/flags_ui.h"
 #include "chrome/browser/ui/webui/gpu_internals_ui.h"
 #include "chrome/browser/ui/webui/history2_ui.h"
 #include "chrome/browser/ui/webui/history_ui.h"
 #include "chrome/browser/ui/webui/html_dialog_ui.h"
 #include "chrome/browser/ui/webui/net_internals_ui.h"
 #include "chrome/browser/ui/webui/ntp/new_tab_ui.h"
 #include "chrome/browser/ui/webui/options/options_ui.h"
 #include "chrome/browser/ui/webui/plugins_ui.h"
 #include "chrome/browser/ui/webui/print_preview_ui.h"
 #include "chrome/browser/ui/webui/sync_internals_ui.h"
+#include "chrome/browser/ui/webui/test_chrome_web_ui_factory.h"
 #include "chrome/browser/ui/webui/textfields_ui.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/url_constants.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/browser/webui/web_ui.h"
 #include "googleurl/src/gurl.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/ui/webui/chromeos/choose_mobile_network_ui.h"
@@ skipping 170 matching lines @@
   if (url.host() == chrome::kChromeUILoginHost)
     return &NewWebUI<chromeos::LoginUI>;
 #endif
 
   if (url.spec() == chrome::kChromeUIConstrainedHTMLTestURL)
     return &NewWebUI<ConstrainedHtmlUI>;
 
   return NULL;
 }
 
+// When the test-type switch is set, return a TestType object, which should be a
+// subclass of Type.
+template<typename Type, typename TestType>
+struct PossibleTestSingletonTraits : public DefaultSingletonTraits<Type> {

[Evan Stade, 2011/05/24 17:25:59]

explicitly state privacy level

[Lei Zhang (Do not use), 2011/05/24 18:00:06]

Do you need this template? Why can't you just do the following in GetInstance()
?

if (CommandLine::ForCurrentProcess()->HasSwitch(some_flag))
  return Singleton<TestChromeWebUIFactory>::get();
else
  return Singleton<ChromeWebUIFactory>::get();

[Sheridan Rawlins, 2011/05/24 20:17:22]

This doesn't play nicely with the privacy/friendship example usage in
base/memory/singleton.h (get is only allowed in the GetIntance of the particular
type.

On 2011/05/24 18:00:06, thestig wrote:

[Sheridan Rawlins, 2011/05/24 20:17:22]

As a derived struct of DefaultSingletonTraits, which is a struct, I'll leave
this a struct too, as we discussed (struct's default privacy level is public).

[Sheridan Rawlins, 2011/05/25 18:29:42]

As discussed in email thread, my main argument for doing it here in traits
instead of in GetInstance() is that the if condition will be done exactly once
(when the singleton doesn't exist) rather than with every call to GetInstance().
 While the time savings may be minimal, it is conceptually what I want.  I'll
add a comment.

On 2011/05/24 18:00:06, thestig wrote:

+  static Type* New() {
+    if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kTestType))
+      return DefaultSingletonTraits<TestType>::New();
+    else
+      return DefaultSingletonTraits<Type>::New();
+  }
+};
+
 }  // namespace
 
 WebUI::TypeID ChromeWebUIFactory::GetWebUIType(Profile* profile,
                                                const GURL& url) const {
   WebUIFactoryFunction function = GetWebUIFactoryFunction(profile, url);
   return function ? reinterpret_cast<WebUI::TypeID>(function) : WebUI::kNoWebUI;
 }
 
 bool ChromeWebUIFactory::UseWebUIForURL(Profile* profile,
                                         const GURL& url) const {
@@ skipping 49 matching lines @@
     favicon.known_icon = favicon.image_data.get() != NULL &&
                              favicon.image_data->size() > 0;
     request->ForwardResultAsync(
         FaviconService::FaviconDataCallback::TupleType(request->handle(),
                                                        favicon));
   }
 }
 
 // static
 ChromeWebUIFactory* ChromeWebUIFactory::GetInstance() {
-  return Singleton<ChromeWebUIFactory>::get();
+  return Singleton<ChromeWebUIFactory, PossibleTestSingletonTraits<
+      ChromeWebUIFactory, TestChromeWebUIFactory> >::get();
 }
 
 ChromeWebUIFactory::ChromeWebUIFactory() {
 }
 
 ChromeWebUIFactory::~ChromeWebUIFactory() {
 }
 
 RefCountedMemory* ChromeWebUIFactory::GetFaviconResourceBytes(
     const GURL& page_url) const  {
@@ skipping 35 matching lines @@
     return FlagsUI::GetFaviconResourceBytes();
 
   if (page_url.host() == chrome::kChromeUISettingsHost)
     return OptionsUI::GetFaviconResourceBytes();
 
   if (page_url.host() == chrome::kChromeUIPluginsHost)
     return PluginsUI::GetFaviconResourceBytes();
 
   return NULL;
 }