Tell DNS prefetch when search URL is likely so that prewarming can be done...

chrome/browser/autocomplete/autocomplete.h

Index: chrome/browser/autocomplete/autocomplete.h
===================================================================
--- chrome/browser/autocomplete/autocomplete.h	(revision 43988)
+++ chrome/browser/autocomplete/autocomplete.h	(working copy)
@@ -373,6 +373,9 @@
                                        int style,
                                        ACMatchClassifications* classifications);
 
+  // The type of this match is a search query with the default engine.
+  bool IsSearchType() const;
+
   // The provider of this match, used to  remember which provider the user had
   // selected when the input changes. This may be NULL, in which case there is
   // no provider (or memory of the user's selection).