Gate support for certain EOTFs/primaries/matrices on color management / hdr flags

Creates a new class VideoColorSpace specifically for encoding color spaces
according to ISO/IEC 23001-8.

Plumb this color space through from parsing to validation.

BUG=687627

Review-Url: https://codereview.chromium.org/2742113002
Cr-Commit-Position: refs/heads/master@{#456518}
static bool IsValidH264Level(uint8_t level_idc) {
  return ((level_idc >= 10 && level_idc <= 13) ||
          (level_idc >= 20 && level_idc <= 22) ||
          (level_idc >= 30 && level_idc <= 32) ||
          (level_idc >= 40 && level_idc <= 42) ||
          (level_idc >= 50 && level_idc <= 51));
}

static bool IsValidH264Level(uint8_t level_idc) {
  return ((level_idc >= 10 && level_idc <= 13) ||
          (level_idc >= 20 && level_idc <= 22) ||
          (level_idc >= 30 && level_idc <= 32) ||
          (level_idc >= 40 && level_idc <= 42) ||
          (level_idc >= 50 && level_idc <= 51));
}
