Remove wgpu::ExternalTextureDescriptor::colorSpace

Fixed: dawn:1445
Change-Id: I33ea40b371f9f72a36205df58f1964e083e0bf4a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/92247
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
diff --git a/dawn.json b/dawn.json
index 745167e..0a85dcf 100644
--- a/dawn.json
+++ b/dawn.json
@@ -1354,8 +1354,7 @@
             {"name": "dst transfer function parameters", "type": "float", "annotation": "const*",
                 "length": 7},
             {"name": "gamut conversion matrix", "type": "float", "annotation": "const*",
-                "length": 9},
-            {"name": "color space", "type": "predefined color space", "default": "srgb"}
+                "length": 9}
         ]
     },
     "feature name": {
@@ -1566,13 +1565,6 @@
             {"value": 2, "name": "high performance"}
         ]
     },
-    "predefined color space": {
-        "category": "enum",
-        "values": [
-            {"value": 0, "name": "undefined", "jsrepr": "undefined"},
-            {"value": 1, "name": "srgb"}
-        ]
-    },
     "present mode": {
         "category": "enum",
         "emscripten_no_enum_table": true,