Reduce header dependencies in net/

net/base/filter.h

 // 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.
 //
 // Filter performs filtering on data streams. Sample usage:
 //
 //   IStream* pre_filter_source;
 //   ...
 //   Filter* filter = Filter::Factory(filter_type, size);
 //   int pre_filter_data_len = filter->stream_buffer_size();
@@ skipping 15 matching lines @@
 //
 // The lifetime of a Filter instance is completely controlled by its caller.
 
 #ifndef NET_BASE_FILTER_H__
 #define NET_BASE_FILTER_H__
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
 #include "base/time.h"
-#include "net/base/io_buffer.h"
-#include "googleurl/src/gurl.h"
 #include "testing/gtest/include/gtest/gtest_prod.h"
 
+class GURL;
+
+namespace net {
+class IOBuffer;
+}
+
 //------------------------------------------------------------------------------
 // Define an interface class that allows access to contextual information
 // supplied by the owner of this filter.  In the case where there are a chain of
 // filters, there is only one owner of all the chained filters, and that context
 // is passed to the constructor of all those filters.  To be clear, the context
 // does NOT reflect the position in a chain, or the fact that there are prior
 // or later filters in a chain.
 class FilterContext {
  public:
   // Enum to control what histograms are emitted near end-of-life of this
@@ skipping 203 matching lines @@
 
   // Context data from the owner of this filter.  Some filters need additional
   // context information (mime type, etc.) to properly function, and they access
   // this data via this reference member.
   const FilterContext& filter_context_;
 
   DISALLOW_COPY_AND_ASSIGN(Filter);
 };
 
 #endif  // NET_BASE_FILTER_H__