color: Clarify default behaviors

media/filters/h264_parser.cc

Index: media/filters/h264_parser.cc
diff --git a/media/filters/h264_parser.cc b/media/filters/h264_parser.cc
index 052f441d258bc77a38f9e313ceb84bcffd5e584c..830c8ff1aba3d836ed01a23e8734e4fb163c87f4 100644
--- a/media/filters/h264_parser.cc
+++ b/media/filters/h264_parser.cc
@@ -125,17 +125,16 @@ base::Optional<gfx::Rect> H264SPS::GetVisibleRect() const {
 // available from http://www.itu.int/rec/T-REC-H.264.
 gfx::ColorSpace H264SPS::GetColorSpace() const {
   if (colour_description_present_flag) {
-    return gfx::ColorSpace(
+    return gfx::ColorSpace::CreateVideo(
         colour_primaries, transfer_characteristics, matrix_coefficients,
         video_full_range_flag ? gfx::ColorSpace::RangeID::FULL
                               : gfx::ColorSpace::RangeID::LIMITED);
   } else {
-    return gfx::ColorSpace(gfx::ColorSpace::PrimaryID::UNSPECIFIED,
-                           gfx::ColorSpace::TransferID::UNSPECIFIED,
-                           gfx::ColorSpace::MatrixID::UNSPECIFIED,
-                           video_full_range_flag
-                               ? gfx::ColorSpace::RangeID::FULL
-                               : gfx::ColorSpace::RangeID::LIMITED);
+    return gfx::ColorSpace(

[hubbe, 2017/02/16 08:20:50]

I'm not sure I like that we're hardcoding our fallback here, but I don't have a
good suggestions for how to make it better right now either...

[ccameron, 2017/02/16 20:45:27]

I've put a "TODO(ccameron/hubbe): determine how to set default values" here.

Another idea would be to have a gfx::ColorSpace::CreateVideoDefault(bool
full_fange);" and use that. But I'll leave that in the TODO.

+        gfx::ColorSpace::PrimaryID::BT709, gfx::ColorSpace::TransferID::BT709,
+        gfx::ColorSpace::MatrixID::BT709,
+        video_full_range_flag ? gfx::ColorSpace::RangeID::FULL
+                              : gfx::ColorSpace::RangeID::LIMITED);
   }
 }