First version of the time slicing on the urls. Not ready for review yet.

chrome/browser/history/history_backend.h

Index: chrome/browser/history/history_backend.h
diff --git a/chrome/browser/history/history_backend.h b/chrome/browser/history/history_backend.h
index 0f94c2a910bd46cc352a076663671358f7721108..0dbfb19f5804b9fbe222ec3422f5623056373b4a 100644
--- a/chrome/browser/history/history_backend.h
+++ b/chrome/browser/history/history_backend.h
@@ -34,6 +34,7 @@ namespace history {
 
 class CommitLaterTask;
 class HistoryPublisher;
+class TimeFilter;
 
 // *See the .cc file for more information on the design.*
 //
@@ -173,6 +174,14 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
       int result_count,
       int days_back);
 
+  // Request the |result_count| most visited URLs and the chain of redirects
+  // leading to each of these URLs, during the time peiods specified in the
+  // |filter|.
+  void QueryMostVisitedURLsDuringTime(
+      scoped_refptr<QueryMostVisitedURLsRequest> request,
+      int result_count,
+      const history::TimeFilter& filter);
+
   // QueryMostVisitedURLs without the request.
   void QueryMostVisitedURLsImpl(int result_count,
                                 int days_back,