Nothing is ever added to hosts_to_delete_, so this code does nothing useful.

chrome/browser/search_engines/template_url_model.cc

 // Copyright (c) 2010 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/search_engines/template_url_model.h"
 
 #include "app/l10n_util.h"
 #include "base/command_line.h"
 #include "base/environment.h"
 #include "base/stl_util-inl.h"
@@ skipping 547 matching lines @@
   if (keyword_result.builtin_keyword_version != resource_keyword_version) {
     MergeEnginesFromPrepopulateData();
     service_->SetBuiltinKeywordVersion(resource_keyword_version);
   }
 
   // Always save the default search provider to prefs. That way we don't have to
   // worry about it being out of sync.
   if (default_search_provider_)
     SaveDefaultSearchProviderToPrefs(default_search_provider_);
 
-  // Delete any hosts that were deleted before we finished loading.
-  for (std::vector<std::wstring>::iterator i = hosts_to_delete_.begin();
-       i != hosts_to_delete_.end(); ++i) {
-    DeleteGeneratedKeywordsMatchingHost(*i);
-  }
-  hosts_to_delete_.clear();
-
   // Index any visits that occurred before we finished loading.
   for (size_t i = 0; i < visits_to_add_.size(); ++i)
     UpdateKeywordSearchTermsForURL(visits_to_add_[i]);
   visits_to_add_.clear();
 
   loaded_ = true;
 
   FOR_EACH_OBSERVER(TemplateURLModelObserver, model_observers_,
                     OnTemplateURLModelChanged());
 
@@ skipping 169 matching lines @@
       const std::vector<const TemplateURL*>& urls) {
   // Add mappings for the new items.
   for (TemplateURLVector::const_iterator i = urls.begin(); i != urls.end();
        ++i) {
     next_id_ = std::max(next_id_, (*i)->id());
     AddToMaps(*i);
     template_urls_.push_back(*i);
   }
 }
 
-void TemplateURLModel::DeleteGeneratedKeywordsMatchingHost(
-    const std::wstring& host) {
-  const std::wstring host_slash = host + L"/";
-  // Iterate backwards as we may end up removing multiple entries.
-  for (int i = static_cast<int>(template_urls_.size()) - 1; i >= 0; --i) {
-    if (CanReplace(template_urls_[i]) &&
-        (template_urls_[i]->keyword() == host ||
-         template_urls_[i]->keyword().compare(0, host_slash.length(),
-                                              host_slash) == 0)) {
-      Remove(template_urls_[i]);
-    }
-  }
-}
-
 void TemplateURLModel::NotifyLoaded() {
   NotificationService::current()->Notify(
       NotificationType::TEMPLATE_URL_MODEL_LOADED,
       Source<TemplateURLModel>(this),
       NotificationService::NoDetails());
 
   for (size_t i = 0; i < pending_extension_ids_.size(); ++i) {
     Extension* extension = profile_->GetExtensionsService()->
         GetExtensionById(pending_extension_ids_[i], true);
     if (extension)
@@ skipping 324 matching lines @@
       AddToMaps(t_url);
       something_changed = true;
     }
   }
 
   if (something_changed && loaded_) {
     FOR_EACH_OBSERVER(TemplateURLModelObserver, model_observers_,
                       OnTemplateURLModelChanged());
   }
 }