Adding histograms for better Omnibox prerender performance tracking.

chrome/browser/autocomplete/network_action_predictor.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/autocomplete/network_action_predictor.h"
 
 #include <math.h>
 
 #include <vector>
 
@@ skipping 271 matching lines @@
     default:
       NOTREACHED() << "Unexpected notification observed.";
       break;
   }
 }
 
 void NetworkActionPredictor::OnOmniboxOpenedUrl(const AutocompleteLog& log) {
   if (log.text.length() < kMinimumUserTextLength)
     return;
 
+  UMA_HISTOGRAM_COUNTS("NetworkActionPredictor.NavigationCount_" +
+                       prerender::GetOmniboxHistogramSuffix(), 1);
+
   const GURL& opened_url =
       log.result.match_at(log.selected_index).destination_url;
 
   const string16 lower_user_text(base::i18n::ToLower(log.text));
 
   // Add the current match as the only transitional match.
   if (prerender::GetOmniboxHeuristicToUse() !=
       prerender::OMNIBOX_HEURISTIC_EXACT_FULL) {
     DCHECK(transitional_matches_.empty());
     TransitionalMatch dummy_match;
@@ skipping 215 matching lines @@
 
   content::BrowserThread::PostTask(content::BrowserThread::DB, FROM_HERE,
       base::Bind(&NetworkActionPredictorDatabase::CommitTransaction, db_));
 }
 
 NetworkActionPredictor::TransitionalMatch::TransitionalMatch() {
 }
 
 NetworkActionPredictor::TransitionalMatch::~TransitionalMatch() {
 }