Revert 114929 - Standardize StringToInt{,64} interface.

chrome/browser/history/text_database.cc

Index: chrome/browser/history/text_database.cc
===================================================================
--- chrome/browser/history/text_database.cc	(revision 114929)
+++ chrome/browser/history/text_database.cc	(working copy)
@@ -111,14 +111,9 @@
     return 0;
   }
 
-  // TODO: Once StringPiece supports a templated interface over the
-  // underlying string type, use it here instead of substr, since that
-  // will avoid needless string copies.  StringPiece cannot be used
-  // right now because FilePath::StringType could use either 8 or 16 bit
-  // characters, depending on the OS.
   int year, month;
-  base::StringToInt(suffix.substr(0, 4), &year);
-  base::StringToInt(suffix.substr(5, 2), &month);
+  base::StringToInt(suffix.begin(), suffix.begin() + 4, &year);
+  base::StringToInt(suffix.begin() + 5, suffix.begin() + 7, &month);
 
   return year * 100 + month;
 }