Remove call to GetBlockingPool in RLZ

ios/chrome/browser/rlz/rlz_tracker_delegate_impl.cc

 // Copyright 2015 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 "ios/chrome/browser/rlz/rlz_tracker_delegate_impl.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "components/omnibox/browser/omnibox_event_global_tracker.h"
 #include "components/omnibox/browser/omnibox_log.h"
@@ skipping 40 matching lines @@
 }
 
 void RLZTrackerDelegateImpl::Cleanup() {
   on_omnibox_search_callback_.Reset();
 }
 
 bool RLZTrackerDelegateImpl::IsOnUIThread() {
   return web::WebThread::CurrentlyOn(web::WebThread::UI);
 }
 
-base::SequencedWorkerPool* RLZTrackerDelegateImpl::GetBlockingPool() {
-  return web::WebThread::GetBlockingPool();
-}
-
 net::URLRequestContextGetter* RLZTrackerDelegateImpl::GetRequestContext() {
   return GetApplicationContext()->GetSystemURLRequestContext();
 }
 
 bool RLZTrackerDelegateImpl::GetBrand(std::string* brand) {
   return ios::google_brand::GetBrand(brand);
 }
 
 bool RLZTrackerDelegateImpl::IsBrandOrganic(const std::string& brand) {
   return brand.empty() || ios::google_brand::IsOrganic(brand);
@@ skipping 50 matching lines @@
     return;
 
   on_omnibox_url_opened_subscription_.reset();
 
   using std::swap;
   base::Closure callback_to_run;
   swap(callback_to_run, on_omnibox_search_callback_);
   if (!callback_to_run.is_null())
     callback_to_run.Run();
 }