Add field to monitor last visited time for each search engine

components/search_engines/template_url_fetcher.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 "components/search_engines/template_url_fetcher.h"
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 183 matching lines @@
   DCHECK(osdd_url.is_valid());
   DCHECK(!keyword.empty());
 
   if (!template_url_service_->loaded()) {
     // We could try to set up a callback to this function again once the model
     // is loaded but meh.
     template_url_service_->Load();
     return;
   }
 
-  const TemplateURL* template_url =
+  TemplateURL* template_url =

[Peter Kasting, 2016/12/01 07:38:24]

Restore the const here

[ltian, 2016/12/01 10:02:58]

Done.

       template_url_service_->GetTemplateURLForKeyword(keyword);
   if (template_url && (!template_url->safe_for_autoreplace() ||
                        template_url->originating_url() == osdd_url))
     return;
 
   // Make sure we aren't already downloading this request.
   for (const auto& request : requests_) {
     if ((request->url() == osdd_url) || (request->keyword() == keyword))
       return;
   }
 
   requests_.push_back(base::MakeUnique<RequestDelegate>(
       this, keyword, osdd_url, favicon_url, url_fetcher_customize_callback));
 }
 
 void TemplateURLFetcher::RequestCompleted(RequestDelegate* request) {
   auto i = std::find_if(requests_.begin(), requests_.end(),
                         [request](const std::unique_ptr<RequestDelegate>& ptr) {
                           return ptr.get() == request;
                         });
   DCHECK(i != requests_.end());
   requests_.erase(i);
 }