Get rid of url_request_tracking.*. The only other place that used it other than ResourceDispatch...

chrome/browser/net/url_request_tracking.h

-// Copyright (c) 2010 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.
-
-#ifndef CHROME_BROWSER_NET_URL_REQUEST_TRACKING_H_
-#define CHROME_BROWSER_NET_URL_REQUEST_TRACKING_H_
-#pragma once
-
-namespace net {
-class URLRequest;
-}  // namespace net
-
-namespace chrome_browser_net {
-
-// Sets the given ID on the given request for later retrieval. This information
-// duplicates a field in the ResourceDispatcherHost's user data, but is also
-// set for non-ResourceDispatcher-related requests. Having this one global
-// place allows us to do more general things, such as assigning traffic for the
-// network view in the task manager.
-//
-// If you make a request on behalf of a child process other than a renderer,
-// please call this function to store its PID (NOT its browser-assigned unique
-// child ID).  For requests originating in a renderer or the browser itself,
-// set a PID of zero (the default).
-//
-// TODO(wez): Get rid of the zero-PID hack & enforce that one is always set.
-void SetOriginPIDForRequest(int pid, net::URLRequest* request);
-
-// Returns the process ID of the request's originator, previously stored with
-// SetOriginProcessIDForRequest, or zero if no PID has been set.  A PID of zero
-// should be interpreted as meaning the request originated from a renderer
-// process, or within the browser itself.
-int GetOriginPIDForRequest(const net::URLRequest* request);
-
-}  // namespace chrome_browser_net
-
-#endif  // CHROME_BROWSER_NET_URL_REQUEST_TRACKING_H_