Replace string16 with base::string16.

chrome/browser/autocomplete/history_url_provider.h

Index: chrome/browser/autocomplete/history_url_provider.h
diff --git a/chrome/browser/autocomplete/history_url_provider.h b/chrome/browser/autocomplete/history_url_provider.h
index 610d35bd467f9b023a03825ec1ff78a2bd4130d7..3926e0327be4491251433305b21b1ad5da969b82 100644
--- a/chrome/browser/autocomplete/history_url_provider.h
+++ b/chrome/browser/autocomplete/history_url_provider.h
@@ -173,7 +173,7 @@ class HistoryURLProvider : public HistoryProvider {
   // set to true if |text| contains an http prefix.
   // NOTE: This does not set the relevance of the returned match, as different
   //       callers want different behavior. Callers must set this manually.
-  AutocompleteMatch SuggestExactInput(const string16& text,
+  AutocompleteMatch SuggestExactInput(const base::string16& text,
                                       const GURL& destination_url,
                                       bool trim_http);
 
@@ -294,8 +294,8 @@ class HistoryURLProvider : public HistoryProvider {
   // Returns a set of classifications that highlight all the occurrences
   // of |input_text| at word breaks in |description|.
   static ACMatchClassifications ClassifyDescription(
-      const string16& input_text,
-      const string16& description);
+      const base::string16& input_text,
+      const base::string16& description);
 
   // Params for the current query.  The provider should not free this directly;
   // instead, it is passed as a parameter through the history backend, and the