Revert of Clear SDCH information on "Clear browsing data" path.

chrome/browser/net/sdch_dictionary_fetcher.cc

 // Copyright (c) 2012 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/net/sdch_dictionary_fetcher.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/message_loop/message_loop.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 31 matching lines @@
   if (attempted_load_.find(dictionary_url) != attempted_load_.end()) {
     net::SdchManager::SdchErrorRecovery(
         net::SdchManager::DICTIONARY_ALREADY_TRIED_TO_DOWNLOAD);
     return;
   }
   attempted_load_.insert(dictionary_url);
   fetch_queue_.push(dictionary_url);
   ScheduleDelayedRun();
 }
 
-void SdchDictionaryFetcher::Cancel() {
-  DCHECK(CalledOnValidThread());
-
-  while (!fetch_queue_.empty())
-    fetch_queue_.pop();
-  attempted_load_.clear();
-  weak_factory_.InvalidateWeakPtrs();
-  current_fetch_.reset(NULL);
-}
-
 void SdchDictionaryFetcher::ScheduleDelayedRun() {
   if (fetch_queue_.empty() || current_fetch_.get() || task_is_pending_)
     return;
   base::MessageLoop::current()->PostDelayedTask(FROM_HERE,
       base::Bind(&SdchDictionaryFetcher::StartFetching,
                  weak_factory_.GetWeakPtr()),
       base::TimeDelta::FromMilliseconds(kMsDelayFromRequestTillDownload));
   task_is_pending_ = true;
 }
 
 void SdchDictionaryFetcher::StartFetching() {
   DCHECK(CalledOnValidThread());
   DCHECK(task_is_pending_);
   task_is_pending_ = false;
 
-  // Handle losing the race against Cancel().
-  if (fetch_queue_.empty())
-    return;
-
   DCHECK(context_.get());
   current_fetch_.reset(net::URLFetcher::Create(
       fetch_queue_.front(), net::URLFetcher::GET, this));
   fetch_queue_.pop();
   current_fetch_->SetRequestContext(context_.get());
   current_fetch_->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
                                net::LOAD_DO_NOT_SAVE_COOKIES);
   current_fetch_->Start();
 }
 
 void SdchDictionaryFetcher::OnURLFetchComplete(
     const net::URLFetcher* source) {
   DCHECK(CalledOnValidThread());
   if ((200 == source->GetResponseCode()) &&
       (source->GetStatus().status() == net::URLRequestStatus::SUCCESS)) {
     std::string data;
     source->GetResponseAsString(&data);
     manager_->AddSdchDictionary(data, source->GetURL());
   }
   current_fetch_.reset(NULL);
   ScheduleDelayedRun();
 }