Cleanup: Change LogMostVisitedImpression|Navigation APIs to take an enum

chrome/renderer/searchbox/searchbox.h

Index: chrome/renderer/searchbox/searchbox.h
diff --git a/chrome/renderer/searchbox/searchbox.h b/chrome/renderer/searchbox/searchbox.h
index 0a5f1689fcdfc883d96820e03373d128c12cbddd..528a034b7529b4363680a0418b1192bb676a6d2c 100644
--- a/chrome/renderer/searchbox/searchbox.h
+++ b/chrome/renderer/searchbox/searchbox.h
@@ -54,10 +54,10 @@ class SearchBox : public content::RenderViewObserver,
   void LogEvent(NTPLoggingEventType event);
 
   // Sends ChromeViewHostMsg_LogMostVisitedImpression to the browser.
-  void LogMostVisitedImpression(int position, const base::string16& provider);
+  void LogMostVisitedImpression(int position, NTPLoggingTileSource tile_source);
 
   // Sends ChromeViewHostMsg_LogMostVisitedNavigation to the browser.
-  void LogMostVisitedNavigation(int position, const base::string16& provider);
+  void LogMostVisitedNavigation(int position, NTPLoggingTileSource tile_source);
 
   // Sends ChromeViewHostMsg_ChromeIdentityCheck to the browser.
   void CheckIsUserSignedInToChromeAs(const base::string16& identity);