predictors: Remove unused field from the resource_prefetch_predictor database.

chrome/browser/predictors/resource_prefetch_predictor.cc

 // Copyright 2014 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/predictors/resource_prefetch_predictor.h"
 
 #include <map>
 #include <set>
 #include <utility>
 
@@ skipping 689 matching lines @@
       PopulatePrefetcherRequest(iterator->second, prefetch_requests);
     }
   }
 
   return !prefetch_requests->empty();
 }
 
 void ResourcePrefetchPredictor::PopulatePrefetcherRequest(
     const PrefetchData& data,
     ResourcePrefetcher::RequestVector* requests) {
-  for (ResourceRows::const_iterator it = data.resources.begin();
-       it != data.resources.end(); ++it) {
-    float confidence = static_cast<float>(it->number_of_hits) /
-        (it->number_of_hits + it->number_of_misses);
+  for (const ResourceRow& row : data.resources) {
+    float confidence = static_cast<float>(row.number_of_hits) /
+                       (row.number_of_hits + row.number_of_misses);
     if (confidence < config_.min_resource_confidence_to_trigger_prefetch ||
-        it->number_of_hits < config_.min_resource_hits_to_trigger_prefetch) {
+        row.number_of_hits < config_.min_resource_hits_to_trigger_prefetch) {
       continue;
     }
 
-    ResourcePrefetcher::Request* req = new ResourcePrefetcher::Request(
-        it->resource_url);
+    ResourcePrefetcher::Request* req =
+        new ResourcePrefetcher::Request(row.resource_url);
     requests->push_back(req);
   }
 }
 
 void ResourcePrefetchPredictor::StartPrefetching(
     const NavigationID& navigation_id) {
   if (!prefetch_manager_.get())  // Prefetching not enabled.
     return;
 
   // Prefer URL based data first.
@@ skipping 693 matching lines @@
     // HistoryService is already loaded. Continue with Initialization.
     OnHistoryAndCacheLoaded();
     return;
   }
   DCHECK(!history_service_observer_.IsObserving(history_service));
   history_service_observer_.Add(history_service);
   return;
 }
 
 }  // namespace predictors