More header cleanup:

chrome/browser/extensions/extension_updater.cc

 // Copyright (c) 2009 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/extensions/extension_updater.h"
 
 #include <algorithm>
 #include <set>
 
 #include "base/logging.h"
 #include "base/file_util.h"
 #include "base/file_version_info.h"
+#include "base/histogram.h"
 #include "base/rand_util.h"
 #include "base/sha2.h"
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
 #include "base/time.h"
 #include "base/thread.h"
 #include "base/version.h"
 #include "chrome/app/chrome_version_info.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/extension_error_reporter.h"
@@ skipping 817 matching lines @@
     extension_fetcher_.reset(
         URLFetcher::Create(kExtensionFetcherId, url, URLFetcher::GET, this));
     extension_fetcher_->set_request_context(
         Profile::GetDefaultRequestContext());
     extension_fetcher_->set_load_flags(net::LOAD_DO_NOT_SEND_COOKIES |
                                        net::LOAD_DO_NOT_SAVE_COOKIES);
     extension_fetcher_->Start();
     current_extension_fetch_ = ExtensionFetch(id, url, hash, version);
   }
 }