Add wrapper class to media for support of VP9 video, and add a command line flag to enable the supp…

media/media.gyp

Index: media/media.gyp
diff --git a/media/media.gyp b/media/media.gyp
index f0c03e264783eedf13f90839b841e8dc9e29d117..45bea0738701b0fb5c8d9c117440747cde11157f 100644
--- a/media/media.gyp
+++ b/media/media.gyp
@@ -13,8 +13,11 @@
       ['OS == "android" or OS == "ios"', {
         # Android and iOS don't use ffmpeg.
         'use_ffmpeg%': 0,
+        # Android and iOS don't use libvpx.
+        'use_libvpx%': 0,
       }, {  # 'OS != "android" and OS != "ios"'
         'use_ffmpeg%': 1,
+        'use_libvpx%': 1,
       }],
     ],
   },
@@ -313,6 +316,8 @@
         'filters/video_frame_generator.h',
         'filters/video_renderer_base.cc',
         'filters/video_renderer_base.h',
+        'filters/vpx_video_decoder.cc',
+        'filters/vpx_video_decoder.h',
         'video/capture/fake_video_capture_device.cc',
         'video/capture/fake_video_capture_device.h',
         'video/capture/linux/video_capture_device_linux.cc',
@@ -413,6 +418,17 @@
             'webm/webm_stream_parser.h',
           ],
         }],
+        ['use_libvpx == 1', {
+          'dependencies': [
+            '<(DEPTH)/third_party/libvpx/libvpx.gyp:libvpx',
+          ],
+        }, {  # use_libvpx == 0
+          # Exclude the sources that depend on libvpx.
+          'sources!': [
+            'filters/vpx_video_decoder.cc',
+            'filters/vpx_video_decoder.h',
+          ],
+        }],
         ['OS == "ios"', {
           'includes': [
             # For shared_memory_support_sources variable.