Removing unused ffmpeg variable from common.gypi

build/common.gypi

 # Copyright (c) 2012 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 1793 matching lines @@
 
         # Android does not support background apps.
         'enable_background%': 0,
 
         # Sessions are store separately in the Java side.
         'enable_session_service%': 0,
 
         'p2p_apis%' : 0,
 
         'gtest_target_type%': 'shared_library',
-
-        # Uses system APIs for decoding audio and video.
-        'use_libffmpeg%': '0',
       }],  # OS=="android"
       ['embedded==1', {
         'use_system_fontconfig%': 0,
       }, {
         'use_system_fontconfig%': 1,
       }],
       ['chromecast==1', {
         'enable_mpeg2ts_stream_parser%': 1,
         'ffmpeg_branding%': 'ChromeOS',
         'ozone_platform_ozonex%': 1,
@@ skipping 4360 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }