Update ffmpeg binaries directories to support variants based off the target architecture.

third_party/ffmpeg/ffmpeg.gyp

 # Copyright (c) 2009 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.
 
 {
   'target_defaults': {
     'conditions': [
       ['OS!="linux" and OS!="freebsd"', {'sources/': [['exclude', '/linux/']]}],
       ['OS!="mac"', {'sources/': [['exclude', '/mac/']]}],
       ['OS!="win"', {'sources/': [['exclude', '/win/']]}],
     ],
   },
   'variables': {
     # Allow overridding the selection of which ffmpeg binaries to copy via an
     # environment variable.  Affects the ffmpeg_binaries target.
     'ffmpeg_branding%': '<(branding)',
+    'ffmpeg_variant%': '<(target_arch)',
 
     'use_system_ffmpeg%': 0,
   },
   'targets': [
     {
       'variables': {
         'generate_stubs_script': 'generate_stubs.py',
         'sig_files': [
           # Note that these must be listed in dependency order.
           # (i.e. if A depends on B, then B must be listed before A.)
@@ skipping 156 matching lines @@
         }],
       ],  # conditions
     },
     {
       'target_name': 'ffmpeg_binaries',
       'type': 'none',
       'msvs_guid': '4E4070E1-EFD9-4EF1-8634-3960956F6F10',
       'variables': {
         'conditions': [
           [ 'ffmpeg_branding=="Chrome"', {
-               'branding_dir': 'chrome',
-          }, { # else ffmpeg_branding!="Chrome"
-               'branding_dir': 'chromium',
+            'ffmpeg_bin_dir': 'chrome/<(OS)/<(ffmpeg_variant)',
+          }, {  # else ffmpeg_branding!="Chrome", assume chromium.
+            'ffmpeg_bin_dir': 'chromium/<(OS)/<(ffmpeg_variant)',
           }],
         ],
       },
       'conditions': [
         ['OS=="win"', {
           'variables': {
             'source_files': [
-              'binaries/<(branding_dir)/avcodec-52.dll',
-              'binaries/<(branding_dir)/avformat-52.dll',
-              'binaries/<(branding_dir)/avutil-50.dll',
+              'binaries/<(ffmpeg_bin_dir)/avcodec-52.dll',
+              'binaries/<(ffmpeg_bin_dir)/avformat-52.dll',
+              'binaries/<(ffmpeg_bin_dir)/avutil-50.dll',
             ],
           },
           'dependencies': ['../../build/win/system.gyp:cygwin'],
         }], ['OS=="linux" or OS=="freebsd"', {
           'conditions': [
             ['use_system_ffmpeg==0', {
               'variables': {
                 'source_files': [
-                  'binaries/<(branding_dir)/libavcodec.so.52',
-                  'binaries/<(branding_dir)/libavformat.so.52',
-                  'binaries/<(branding_dir)/libavutil.so.50',
+                  'binaries/<(ffmpeg_bin_dir)/libavcodec.so.52',
+                  'binaries/<(ffmpeg_bin_dir)/libavformat.so.52',
+                  'binaries/<(ffmpeg_bin_dir)/libavutil.so.50',
                 ],
               },
             }, {
               'variables': {
                 'source_files': []
               },
             }],
           ]},
         ], ['OS=="mac"', {
               'variables': {
                 'source_files': [
-                  'binaries/<(branding_dir)/libavcodec.52.dylib',
-                  'binaries/<(branding_dir)/libavformat.52.dylib',
-                  'binaries/<(branding_dir)/libavutil.50.dylib',
+                  'binaries/<(ffmpeg_bin_dir)/libavcodec.52.dylib',
+                  'binaries/<(ffmpeg_bin_dir)/libavformat.52.dylib',
+                  'binaries/<(ffmpeg_bin_dir)/libavutil.50.dylib',
                 ],
               },
         }],
       ],
       'copies': [
         {
           'destination': '<(PRODUCT_DIR)/',
           'files': [
             '<@(source_files)',
           ]
         },
       ],
     },
   ],
 }