Create libffmpeg.so in the component build.

ffmpeg.gyp

 # Copyright (c) 2011 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.
 
 # There's a couple key GYP variables that control how FFmpeg is built:
 #   ffmpeg_branding
 #     Controls whether we build the Chromium or Google Chrome version of
 #     FFmpeg.  The Google Chrome version contains additional codecs.
 #     Typical values are Chromium, Chrome, ChromiumOS, and ChromeOS.
 #   use_system_ffmpeg
@@ skipping 440 matching lines @@
             ],
           }],
         }, {  # else OS!="win", use POSIX stub generator
           'variables': {
             'outfile_type': 'posix_stubs',
             'stubs_filename_root': 'ffmpeg_stubs',
             'project_path': 'third_party/ffmpeg',
             'intermediate_dir': '<(INTERMEDIATE_DIR)',
             'output_root': '<(SHARED_INTERMEDIATE_DIR)/ffmpeg',
           },
-          'type': '<(library)',
+          'type': '<(component)',
           'include_dirs': [
             '<(output_root)',
             '../..',  # The chromium 'src' directory.
           ],
           'direct_dependent_settings': {
             'defines': [
               '__STDC_CONSTANT_MACROS',  # FFmpeg uses INT64_C.
             ],
             'include_dirs': [
               '<(output_root)',
@@ skipping 30 matching lines @@
           'conditions': [
             # Linux/Solaris need libdl for dlopen() and friends.
             ['OS=="linux" or OS=="solaris"', {
               'link_settings': {
                 'libraries': [
                   '-ldl',
                 ],
               },
             }],
 
+            ['component=="shared_library"', {
+              'cflags!': ['-fvisibility=hidden'],
+            }],
+
             # Add pkg-config result to include path when use_system_ffmpeg!=0
             ['use_system_ffmpeg!=0', {
               'cflags': [
                 '<!@(pkg-config --cflags libavcodec libavformat libavutil)',
               ],
               'direct_dependent_settings': {
                 'cflags': [
                   '<!@(pkg-config --cflags libavcodec libavformat libavutil)',
                 ],
               },
@@ skipping 21 matching lines @@
       ],  # conditions
     },
   ],  # targets
 }
 
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