Delete DataLog abstraction, which was almost unused.

webrtc/build/common.gypi

 # Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 # This file contains common settings for building WebRTC components.
 
@@ skipping 89 matching lines @@
     # Use llvm's sancov -html-report for human readable reports.
     # See http://clang.llvm.org/docs/SanitizerCoverage.html .
     'webrtc_sanitize_coverage%': "",
 
     # Remote bitrate estimator logging/plotting.
     'enable_bwe_test_logging%': 0,
 
     # Selects fixed-point code where possible.
     'prefer_fixed_point%': 0,
 
-    # Enable data logging. Produces text files with data logged within engines
-    # which can be easily parsed for offline processing.
-    'enable_data_logging%': 0,
-
     # Enables the use of protocol buffers for debug recordings.
     'enable_protobuf%': 1,
 
     # Disable the code for the intelligibility enhancer by default.
     'enable_intelligibility_enhancer%': 0,
 
     # Selects whether debug dumps for the audio processing module
     # should be generated.
     'apm_debug_dump%': 0,
 
@@ skipping 476 matching lines @@
         }],
         ['OS=="freebsd"', {
           'defines': [
             'FREEBSD',
           ],
         }],
       ],
     },
   }, # target_defaults
 }