Remove libvpx from FFmpeg in favour of ffvp8.

ffmpeg/source/ffmpeg.gyp

Index: ffmpeg/source/ffmpeg.gyp
diff --git a/ffmpeg/source/ffmpeg.gyp b/ffmpeg/source/ffmpeg.gyp
index 8573c8c1840055ceb46fad611d74bd04346ee0a2..69115db367aa40e36d6125fdbaaf2425fb868778 100644
--- a/ffmpeg/source/ffmpeg.gyp
+++ b/ffmpeg/source/ffmpeg.gyp
@@ -87,10 +87,6 @@
             'config/<(ffmpeg_branding)/<(os_config)/<(ffmpeg_config)',
             'patched-ffmpeg',
             'config',
-            # TODO(fischman): when both mac & linux are building from
-            # libvpx source replace this hackery with a simple target
-            # dependency on libvpx and let that export its headers.
-            '../libvpx/include',
           ],
           'defines': [
             'HAVE_AV_CONFIG_H',
@@ -187,9 +183,6 @@
                 # exported.
                 '-fvisibility=hidden',
               ],
-              'dependencies': [
-                '../libvpx/libvpx.gyp:libvpx',
-              ],
               'link_settings': {
                 'ldflags': [
                   '-Wl,-Bsymbolic',
@@ -237,9 +230,6 @@
                   },
                 }],
               ],
-              'dependencies': [
-                '../libvpx/libvpx.gyp:libvpx',
-              ],
               'link_settings': {
                 'libraries': [
                   '$(SDKROOT)/usr/lib/libz.dylib',
@@ -326,29 +316,15 @@
   ],  # conditions
   'targets': [
     {
-      # Determine whether we should export libvpx symbols.
       'variables': {
         'generate_stubs_script': '../../tools/generate_stubs/generate_stubs.py',
         'extra_header': 'ffmpeg_stub_headers.fragment',
-        'conditions': [
-          ['use_system_ffmpeg==1', {
-            '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.)
-              # See: http://code.google.com/p/chromium/issues/detail?id=70687
-              'avutil-51.sigs',
-              'avcodec-53.novpx_sigs',
-              'avformat-53.sigs',
-            ],
-          }, {  # otherwise we export libvpx symbols.
-            '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.)
-              'avutil-51.sigs',
-              'avcodec-53.sigs',
-              'avformat-53.sigs',
-            ],
-          }],
+        '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.)
+          'avutil-51.sigs',
+          'avcodec-53.sigs',
+          'avformat-53.sigs',
         ],
       },
 
@@ -366,12 +342,6 @@
       'defines': [
         '__STDC_CONSTANT_MACROS',  # FFmpeg uses INT64_C.
       ],
-      'include_dirs': [
-        # TODO(fischman): when both mac & linux are building from
-        # libvpx source replace this hackery with a simple target
-        # dependency on libvpx and let that export its headers.
-        '../libvpx/include',
-      ],
       'hard_dependency': 1,
 
       # Do not fear the massive conditional blocks!  They do the following: