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

chrome/browser/ui/chrome_pages.cc

Index: chrome/browser/ui/chrome_pages.cc
diff --git a/chrome/browser/ui/chrome_pages.cc b/chrome/browser/ui/chrome_pages.cc
index f0b002e9e91e0e31389f78b63659c7bd956043d8..1edb1e7d1641af53008bd52e26afdf7880f811e5 100644
--- a/chrome/browser/ui/chrome_pages.cc
+++ b/chrome/browser/ui/chrome_pages.cc
@@ -15,6 +15,7 @@
 #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"
@@ -25,6 +26,7 @@
 #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"
 
@@ -75,29 +77,32 @@ void NavigateToSingletonTab(Browser* browser, const GURL& url) {
 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;
@@ -108,7 +113,7 @@ void ShowHelpImpl(Browser* browser,
       url = GURL(kChromeHelpViaWebUIURL);
       break;
     default:
-      NOTREACHED() << "Unhandled help source " << source;
+      NOTREACHED() << "Unhandled help source " << help_source;
   }
   scoped_ptr<ScopedTabbedBrowserDisplayer> displayer;
   if (!browser) {