Switch guest profile from forced-incognito to UI mods like ChromeOS.

chrome/browser/extensions/chrome_extensions_browser_client.cc

Index: chrome/browser/extensions/chrome_extensions_browser_client.cc
diff --git a/chrome/browser/extensions/chrome_extensions_browser_client.cc b/chrome/browser/extensions/chrome_extensions_browser_client.cc
index 728407488db70bf41405a12b9a294ae613744408..720d3ed6a59e4f2014b616d98967df5d6e1b65c6 100644
--- a/chrome/browser/extensions/chrome_extensions_browser_client.cc
+++ b/chrome/browser/extensions/chrome_extensions_browser_client.cc
@@ -120,16 +120,14 @@ bool ChromeExtensionsBrowserClient::DeferLoadingBackgroundHosts(
 
 bool ChromeExtensionsBrowserClient::IsBackgroundPageAllowed(
     content::BrowserContext* context) const {
-#if defined(OS_CHROMEOS)
-  // Returns true if current session is Chrome OS Guest mode session and current
+  // Returns true if current session is Guest mode session and current
   // browser context is *not* off-the-record. Such context is artificial and
   // background page shouldn't be created in it.
-  const CommandLine* command_line = CommandLine::ForCurrentProcess();
-  if (command_line->HasSwitch(chromeos::switches::kGuestSession) &&
+  if ((static_cast<Profile*>(context))->IsGuestSession() &&

[msw, 2014/02/15 00:30:52]

nit: convert this if statement and following return to:
return !Profile::FromBrowserContext(context)->IsGuestSession() ||
context->IsOffTheRecord();

[bcwhite, 2014/02/18 15:19:36]

Done.

       !context->IsOffTheRecord()) {
     return false;
   }
-#endif
+
   return true;
 }