Coalesce more hardcoded schemes to using predefined constants.

chrome/browser/browsing_instance.cc

Index: chrome/browser/browsing_instance.cc
===================================================================
--- chrome/browser/browsing_instance.cc	(revision 10345)
+++ chrome/browser/browsing_instance.cc	(working copy)
@@ -7,6 +7,7 @@
 #include "base/command_line.h"
 #include "chrome/browser/tab_contents/site_instance.h"
 #include "chrome/common/chrome_switches.h"
+#include "chrome/common/url_constants.h"
 
 /*static*/
 BrowsingInstance::ProfileSiteInstanceMap
@@ -28,7 +29,7 @@
     // Note that --single-process may have been specified, but that affects the
     // process creation logic in RenderProcessHost, so we do not need to worry
     // about it here.
-    if (url.SchemeIs("chrome-ui"))
+    if (url.SchemeIs(chrome::kChromeUIScheme))
       // Always consolidate instances of the new tab page (and instances of any
       // other internal resource urls).
       return true;