Reduce the amount of included header files. Vast change like in "Oh God! This...

net/url_request/mime_sniffer_proxy.cc

 // Copyright (c) 2006-2008 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 "net/url_request/mime_sniffer_proxy.h"
 
+#include "net/base/io_buffer.h"
 #include "net/base/mime_sniffer.h"
 
 static const int kBufferSize = 1024;
 
 MimeSnifferProxy::MimeSnifferProxy(URLRequest* request,
                                    URLRequest::Delegate* delegate)
     : request_(request), delegate_(delegate),
       sniff_content_(false), error_(false),
       buf_(new net::IOBuffer(kBufferSize)) {
   request->set_delegate(this);
@@ skipping 48 matching lines @@
                          type_hint, &mime_type_);
     } else {
       error_ = true;
     }
     delegate_->OnResponseStarted(request_);
     return;
   }
   delegate_->OnReadCompleted(request, bytes_read);
 }