Delete the ClientSocketPoolHistograms class.

net/net.gypi

 # Copyright 2014 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 file is shared between the regular GYP build, the NaCl GYP build, and
 # the GN build. For GN support, it must have no conditionals or anything like
 # that beyond the simple one-level-deep dictionary of values.
 {
   'variables': {
     # Subset of net source files that are compiled for NaCl (net_nacl target).
@@ skipping 102 matching lines @@
       'http/http_security_headers.h',
       'http/http_util.cc',
       'http/http_util.h',
       'http/http_util_icu.cc',
       'http/http_vary_data.cc',
       'http/http_vary_data.h',
       'http/transport_security_state.cc',
       'http/transport_security_state.h',
       'socket/client_socket_handle.cc',
       'socket/client_socket_handle.h',
-      'socket/client_socket_pool_histograms.cc',
-      'socket/client_socket_pool_histograms.h',
       'socket/next_proto.cc',
       'socket/next_proto.h',
       'socket/socket.h',
       'socket/ssl_client_socket.cc',
       'socket/ssl_client_socket.h',
       'socket/ssl_client_socket_openssl.cc',
       'socket/ssl_client_socket_openssl.h',
       'socket/ssl_client_socket_pool.cc',
       'socket/ssl_client_socket_pool.h',
       'socket/ssl_session_cache_openssl.cc',
@@ skipping 1649 matching lines @@
       'base/mac/url_conversions_unittest.mm',
     ],
     'net_docs_script': 'tools/net_docs/net_docs.py',
     'net_docs_sources': [
       'README.md',
       'sdch/README.md',
     ],
     'net_docs_output_dir': '<(PRODUCT_DIR)/net/docs',
   }
 }