color: Clarify default behaviors

media/filters/vpx_video_decoder.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/vpx_video_decoder.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 586 matching lines @@
   (*video_frame)
       ->metadata()
       ->SetInteger(VideoFrameMetadata::COLOR_SPACE, color_space);
 
   if (config_.color_space_info() != gfx::ColorSpace()) {
     // config_.color_space_info() comes from the color tag which is
     // more expressive than the bitstream, so prefer it over the
     // bitstream data below.
     (*video_frame)->set_color_space(config_.color_space_info());
   } else {
-    gfx::ColorSpace::PrimaryID primaries =
-        gfx::ColorSpace::PrimaryID::UNSPECIFIED;
-    gfx::ColorSpace::TransferID transfer =
-        gfx::ColorSpace::TransferID::UNSPECIFIED;
-    gfx::ColorSpace::MatrixID matrix = gfx::ColorSpace::MatrixID::UNSPECIFIED;
+    gfx::ColorSpace::PrimaryID primaries = gfx::ColorSpace::PrimaryID::INVALID;
+    gfx::ColorSpace::TransferID transfer = gfx::ColorSpace::TransferID::INVALID;
+    gfx::ColorSpace::MatrixID matrix = gfx::ColorSpace::MatrixID::INVALID;
     gfx::ColorSpace::RangeID range = vpx_image->range == VPX_CR_FULL_RANGE
                                          ? gfx::ColorSpace::RangeID::FULL
                                          : gfx::ColorSpace::RangeID::LIMITED;
 
     switch (vpx_image->cs) {
       case VPX_CS_BT_601:
       case VPX_CS_SMPTE_170:
         primaries = gfx::ColorSpace::PrimaryID::SMPTE170M;
         transfer = gfx::ColorSpace::TransferID::SMPTE170M;
         matrix = gfx::ColorSpace::MatrixID::SMPTE170M;
@@ skipping 22 matching lines @@
       case VPX_CS_SRGB:
         primaries = gfx::ColorSpace::PrimaryID::BT709;
         transfer = gfx::ColorSpace::TransferID::IEC61966_2_1;
         matrix = gfx::ColorSpace::MatrixID::BT709;
         break;
 
       default:
         break;
     }
 
-    if (primaries != gfx::ColorSpace::PrimaryID::UNSPECIFIED) {
+    // TODO(ccameron): Set a color space even for unspecified values.
+    if (primaries != gfx::ColorSpace::PrimaryID::INVALID) {
       (*video_frame)
           ->set_color_space(
               gfx::ColorSpace(primaries, transfer, matrix, range));
     }
   }
 
   return true;
 }
 
 VpxVideoDecoder::AlphaDecodeStatus VpxVideoDecoder::DecodeAlphaPlane(
@@ skipping 181 matching lines @@
       (*video_frame)->visible_data(VideoFrame::kUPlane),
       (*video_frame)->stride(VideoFrame::kUPlane),
       (*video_frame)->visible_data(VideoFrame::kVPlane),
       (*video_frame)->stride(VideoFrame::kVPlane), coded_size.width(),
       coded_size.height());
 
   return true;
 }
 
 }  // namespace media