Make SDCH classes IO-thread-only. Remove TSan suppression.

chrome/browser/net/sdch_dictionary_fetcher.cc

 // Copyright (c) 2011 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.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/common/url_fetcher.h"
 #include "net/url_request/url_request_status.h"
 
 SdchDictionaryFetcher::SdchDictionaryFetcher()
     : ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)),
       task_is_pending_(false) {
+  DCHECK(CalledOnValidThread());
 }
 
 SdchDictionaryFetcher::~SdchDictionaryFetcher() {
+  DCHECK(CalledOnValidThread());
 }
 
 // static
 void SdchDictionaryFetcher::Shutdown() {
   net::SdchManager::Shutdown();
 }
 
 void SdchDictionaryFetcher::Schedule(const GURL& dictionary_url) {
+  DCHECK(CalledOnValidThread());
+
   // Avoid pushing duplicate copy onto queue.  We may fetch this url again later
   // and get a different dictionary, but there is no reason to have it in the
   // queue twice at one time.
   if (!fetch_queue_.empty() && fetch_queue_.back() == dictionary_url) {
     net::SdchManager::SdchErrorRecovery(
         net::SdchManager::DICTIONARY_ALREADY_SCHEDULED_TO_DOWNLOAD);
     return;
   }
   if (attempted_load_.find(dictionary_url) != attempted_load_.end()) {
     net::SdchManager::SdchErrorRecovery(
@@ skipping 40 matching lines @@
     const content::URLFetcher* source) {
   if ((200 == source->GetResponseCode()) &&
       (source->GetStatus().status() == net::URLRequestStatus::SUCCESS)) {
     std::string data;
     source->GetResponseAsString(&data);
     net::SdchManager::Global()->AddSdchDictionary(data, source->GetURL());
   }
   current_fetch_.reset(NULL);
   ScheduleDelayedRun();
 }