Revert "Remove wgpu::CreatePipelineAsyncStatus::Error"

This reverts commit 9fafbc0a9ebb81e9de03b8b6765ea1721e22a6c8.

Reason for revert: Breaks Chromium compilation.

Original change's description:
> Remove wgpu::CreatePipelineAsyncStatus::Error
>
> It is no longer used in Chromium and the ::ValidationError and
> ::InternalError should be used instead.
>
> Fixed: chromium:1404422
> Change-Id: I7ecb1e23cfedc8f16f91431ac8b9ec8a9bbf2933
> Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/119461
> Kokoro: Kokoro <noreply+kokoro@google.com>
> Reviewed-by: Austin Eng <enga@chromium.org>
> Commit-Queue: Corentin Wallez <cwallez@chromium.org>
> Auto-Submit: Corentin Wallez <cwallez@chromium.org>

TBR=cwallez@chromium.org,enga@chromium.org,noreply+kokoro@google.com,dawn-scoped@luci-project-accounts.iam.gserviceaccount.com

Change-Id: I75dcface5197d6fedd3666c8f7fc694f4fab7c04
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/120381
Commit-Queue: Austin Eng <enga@chromium.org>
Kokoro: Austin Eng <enga@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Kokoro: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/dawn.json b/dawn.json
index 993cd05..f4ec78c 100644
--- a/dawn.json
+++ b/dawn.json
@@ -975,7 +975,8 @@
             {"value": 2, "name": "internal error"},
             {"value": 3, "name": "device lost"},
             {"value": 4, "name": "device destroyed"},
-            {"value": 5, "name": "unknown"}
+            {"value": 5, "name": "unknown"},
+            {"value": 6, "name": "error"}
         ]
     },
     "create render pipeline async callback": {