Add UMA metrics and histograms for locally managed users.

chrome/browser/history/url_database.h

Index: chrome/browser/history/url_database.h
===================================================================
--- chrome/browser/history/url_database.h	(revision 177135)
+++ chrome/browser/history/url_database.h	(working copy)
@@ -54,10 +54,16 @@
   // success and false otherwise.
   bool GetURLRow(URLID url_id, URLRow* info);
 
-  // Looks up all urls that were typed in manually. Fills info with the data.
+  // Looks up all urls that were typed in manually. Fills urls with the data.
   // Returns true on success and false otherwise.
   bool GetAllTypedUrls(URLRows* urls);
 
+  // Looks up all unique URLs whose last visit times fall within the given
+  // range. Fills urls with the data. Returns true on success and false
+  // otherwise.
+  bool GetUniqueURLsInRange(base::Time begin_time, base::Time end_time,
+                            int max_results, URLRows* urls);
+
   // Looks up the given URL and if it exists, fills the given pointers with the
   // associated info and returns the ID of that URL. If the info pointer is
   // NULL, no information about the URL will be filled in, only the ID will be