Adds GYP variable to enable MPEG2TS stream parsing.

BUG=357668

Review URL: https://codereview.chromium.org/216423008

git-svn-id: http://src.chromium.org/svn/trunk/src/build@260740 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

common.gypi

@@ -1349,6 +1349,9 @@
     # Set to 1 to compile with the hole punching for the protected video.
     'video_hole%': 0,
 
+    # Set to 1 to compile with MSE support for MPEG2 TS
+    'enable_mpeg2ts_stream_parser%': 0,
+
     'conditions': [
       # Enable the Syzygy optimization step for the official builds.
       ['OS=="win" and buildtype=="Official" and syzyasan!=1', {