Fix race conditions in ImageDecoder.

chrome/browser/bitmap_fetcher/bitmap_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 "chrome/browser/bitmap_fetcher/bitmap_fetcher.h"
 
 #include "content/public/browser/browser_thread.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "net/url_request/url_request_status.h"
 
 namespace chrome {
 
 BitmapFetcher::BitmapFetcher(const GURL& url, BitmapFetcherDelegate* delegate)
-    : ImageRequest(content::BrowserThread::GetMessageLoopProxyForThread(
-          content::BrowserThread::UI)),
-      url_(url),
+    : url_(url),
       delegate_(delegate) {
 }
 
 BitmapFetcher::~BitmapFetcher() {
 }
 
 void BitmapFetcher::Start(net::URLRequestContextGetter* request_context,
                           const std::string& referrer,
                           net::URLRequest::ReferrerPolicy referrer_policy,
                           int load_flags) {
@@ skipping 41 matching lines @@
 
 void BitmapFetcher::OnDecodeImageFailed() {
   ReportFailure();
 }
 
 void BitmapFetcher::ReportFailure() {
   delegate_->OnFetchComplete(url_, NULL);
 }
 
 }  // namespace chrome