Add Hover stats for 1.5s, 2s, and 3s hover thresholds.

chrome/browser/prerender/prerender_observer.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/prerender/prerender_observer.h"
 
 #include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/time.h"
 #include "chrome/browser/prerender/prerender_manager.h"
@@ skipping 10 matching lines @@
   50,
   75,
   100,
   150,
   200,
   250,
   300,
   400,
   500,
   750,
-  1000
+  1000,
+  1500,
+  2000,
+  3000,
+  4000,
+  5000
 };
 
 // Overview of hover-related histograms:
 // -- count of hover start
 // -- count of hover too short.
 // difference between these is pages prerendered
 // -- count of prerender used
 // -- time from hover commence until click (subtract hover threshold
 // from that value to figure out average savings).
 
@@ skipping 250 matching lines @@
                               elapsed_ms, num_buckets);
   } else {
     UMA_HISTOGRAM_ENUMERATION("Prerender.HoverStats_TimeUntilDiscarded",
                               elapsed_ms, num_buckets);
   }
 
   current_hover_url_ = GURL();
 }
 
 }  // namespace prerender