Rip out browser-side RID caching for most visited items.

chrome/browser/search/search.h

Index: chrome/browser/search/search.h
diff --git a/chrome/browser/search/search.h b/chrome/browser/search/search.h
index 16fca8d40d8632861d13537a2515707225514ff1..a015225e1a2fc633e78c2345df51f2741f17ca02 100644
--- a/chrome/browser/search/search.h
+++ b/chrome/browser/search/search.h
@@ -11,6 +11,7 @@
 
 #include "base/basictypes.h"
 #include "base/string16.h"
+#include "chrome/common/instant_types.h"
 
 class GURL;
 class Profile;
@@ -228,6 +229,11 @@ bool DefaultSearchProviderSupportsInstant(Profile* profile);
 // once.
 void ResetInstantExtendedOptInStateGateForTest();
 
+// Returns true if |items_a| and |items_b| are equal.
+bool AreMostVisitedItemsEqual(
+    const std::vector<InstantMostVisitedItem>& items_a,
+    const std::vector<InstantMostVisitedItem>& items_b);
+
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_SEARCH_SEARCH_H_