Make "source" a required argument of AppLaunchParams and fill in the argument in all call points.

chrome/browser/ui/chrome_pages.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/chrome_pages.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/download/download_shelf.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_navigator.h"
 #include "chrome/browser/ui/browser_window.h"
+#include "chrome/browser/ui/extensions/app_launch_params.h"
 #include "chrome/browser/ui/extensions/application_launch.h"
 #include "chrome/browser/ui/scoped_tabbed_browser_displayer.h"
 #include "chrome/browser/ui/settings_window_manager.h"
 #include "chrome/browser/ui/singleton_tabs.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/webui/options/content_settings_handler.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/browser/web_contents.h"
+#include "extensions/common/constants.h"
 #include "google_apis/gaia/gaia_urls.h"
 #include "net/base/url_util.h"
 
 #if defined(OS_WIN)
 #include "chrome/browser/enumerate_modules_model_win.h"
 #endif
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/genius_app/app_id.h"
 #include "extensions/browser/extension_registry.h"
@@ skipping 30 matching lines @@
   ShowSingletonTabOverwritingNTP(browser, params);
 }
 
 // Shows either the help app or the appropriate help page for |source|. If
 // |browser| is NULL and the help page is used (vs the app), the help page is
 // shown in the last active browser. If there is no such browser, a new browser
 // is created.
 void ShowHelpImpl(Browser* browser,
                   Profile* profile,
                   HostDesktopType host_desktop_type,
-                  HelpSource source) {
+                  HelpSource help_source) {

[sky, 2014/11/19 16:52:08]

Change the declaration to match the new name, although I would be inclined to
keep existing name and change what you have as source on line 87 to
app_launch_source.

[cylee1, 2014/11/19 17:51:17]

Done.

   content::RecordAction(UserMetricsAction("ShowHelpTab"));
 #if defined(OS_CHROMEOS) && defined(OFFICIAL_BUILD)
   const extensions::Extension* extension =
       extensions::ExtensionRegistry::Get(profile)->GetExtensionById(
           genius_app::kGeniusAppId,
           extensions::ExtensionRegistry::EVERYTHING);
-  AppLaunchParams params(profile, extension, 0, host_desktop_type);
-  switch (source) {
+  extensions::AppLaunchSource source(extensions::SOURCE_UNTRACKED);
+  switch (help_source) {
     case HELP_SOURCE_KEYBOARD:
-      params.source = extensions::SOURCE_KEYBOARD;
+      source = extensions::SOURCE_KEYBOARD;
       break;
     case HELP_SOURCE_MENU:
-      params.source = extensions::SOURCE_SYSTEM_TRAY;
+      source = extensions::SOURCE_SYSTEM_TRAY;
       break;
     case HELP_SOURCE_WEBUI:
-      params.source = extensions::SOURCE_ABOUT_PAGE;
+      source = extensions::SOURCE_ABOUT_PAGE;
       break;
+    default:
+      NOTREACHED() << "Unhandled help source " << help_source;
   }
+  AppLaunchParams params(profile, extension, 0, host_desktop_type, source);
   OpenApplication(params);
 #else
   GURL url;
-  switch (source) {
+  switch (help_source) {
     case HELP_SOURCE_KEYBOARD:
       url = GURL(kChromeHelpViaKeyboardURL);
       break;
     case HELP_SOURCE_MENU:
       url = GURL(kChromeHelpViaMenuURL);
       break;
     case HELP_SOURCE_WEBUI:
       url = GURL(kChromeHelpViaWebUIURL);
       break;
     default:
-      NOTREACHED() << "Unhandled help source " << source;
+      NOTREACHED() << "Unhandled help source " << help_source;
   }
   scoped_ptr<ScopedTabbedBrowserDisplayer> displayer;
   if (!browser) {
     displayer.reset(
         new ScopedTabbedBrowserDisplayer(profile, host_desktop_type));
     browser = displayer->browser();
   }
   ShowSingletonTab(browser, url);
 #endif
 }
@@ skipping 218 matching lines @@
       browser = displayer->browser();
     }
 
     NavigateToSingletonTab(browser, GURL(signin::GetPromoURL(source, false)));
     DCHECK_GT(browser->tab_strip_model()->count(), 0);
   }
 }
 #endif
 
 }  // namespace chrome