Remove obviously unneeded forward declarations from headers under src/{app,base,net}.

net/url_request/url_request_context.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.
 
 // This class represents contextual information (cookies, cache, etc.)
 // that's useful when processing resource requests.
 // The class is reference-counted so that it can be cleaned up after any
 // requests that are using it have been completed.
 
 #ifndef NET_URL_REQUEST_URL_REQUEST_CONTEXT_H_
 #define NET_URL_REQUEST_URL_REQUEST_CONTEXT_H_
 #pragma once
 
 #include "base/non_thread_safe.h"
 #include "base/ref_counted.h"
 #include "net/base/cookie_store.h"
 #include "net/base/host_resolver.h"
 #include "net/base/net_log.h"
 #include "net/base/ssl_config_service.h"
 #include "net/base/transport_security_state.h"
 #include "net/ftp/ftp_auth_cache.h"
 #include "net/proxy/proxy_service.h"
 
 namespace net {
 class CookiePolicy;
 class FtpTransactionFactory;
 class HttpAuthHandlerFactory;
 class HttpNetworkDelegate;
 class HttpTransactionFactory;
-class SocketStream;
 }
 class URLRequest;
 
 // Subclass to provide application-specific context for URLRequest instances.
 class URLRequestContext
     : public base::RefCountedThreadSafe<URLRequestContext>,
       public NonThreadSafe {
  public:
   URLRequestContext()
       : net_log_(NULL),
@@ skipping 95 matching lines @@
   // The charset of the referrer where this request comes from. It's not
   // used in communication with a server but is used to construct a suggested
   // filename for file download.
   std::string referrer_charset_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(URLRequestContext);
 };
 
 #endif  // NET_URL_REQUEST_URL_REQUEST_CONTEXT_H_