Add VaapiVideoEncodeAccelerator for HW-accelerated video encode.

media/media.gyp

Index: media/media.gyp
diff --git a/media/media.gyp b/media/media.gyp
index 71099e934756dd7275f9523012131e948286c6c9..68956b39404c67a9e22fafdb876ea362e1ed842d 100644
--- a/media/media.gyp
+++ b/media/media.gyp
@@ -657,6 +657,13 @@
             'formats/webm/chromeos/webm_encoder.h',
           ],
         }],
+        # For VaapiVideoEncodeAccelerator.
+        ['target_arch != "arm" and chromeos == 1 and use_x11 == 1', {
+          'sources': [
+            'filters/h264_bitstream_buffer.cc',
+            'filters/h264_bitstream_buffer.h',
+          ],
+        }],
         ['OS!="ios"', {
           'dependencies': [
             '../third_party/libyuv/libyuv.gyp:libyuv',
@@ -1117,6 +1124,7 @@
         'filters/file_data_source_unittest.cc',
         'filters/frame_processor_unittest.cc',
         'filters/h264_bit_reader_unittest.cc',
+        'filters/h264_bitstream_buffer_unittest.cc',
         'filters/h264_parser_unittest.cc',
         'filters/in_memory_url_protocol_unittest.cc',
         'filters/opus_audio_decoder_unittest.cc',