Change GPUDeviceLostReason undefined to "unknown"

Spec change resolved here:
gpuweb/gpuweb#3894 (comment)

Fixed: 1424883
Change-Id: I316fbaf443a396fc993e0ac9e0d2c0fb9fa1ba42
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4342174
Auto-Submit: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Kai Ninomiya <kainino@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1119661}

content/test/data/gpu/webgpu-domain-not-blocked.html

@@ -35,8 +35,8 @@
   // NOT result in the domain being blocked.
   console.log('Waiting for GPU termination to cause device loss');
   const lost = await device.lost;
-  if (lost.reason !== undefined) {
-    console.log('TEST FAILED - Expected undefined device lost reason');
+  if (lost.reason !== 'unknown') {
+    console.log('TEST FAILED - Expected device lost reason "unknown"');
     reportProgress('FAILED');
     return;
   }

content/test/data/gpu/webgpu-domain-unblocking.html

@@ -51,8 +51,8 @@
     // this should result in the domain being blocked.
     console.log('Iteration ' + idx + ': Waiting for GPU crash to cause device loss');
     const lost = await device.lost;
-    if (lost.reason !== undefined) {
-      console.log('TEST FAILED - Expected undefined device lost reason');
+    if (lost.reason !== 'unknown') {
+      console.log('TEST FAILED - Expected device lost reason "unknown"');
       reportProgress('FAILED');
       return;
     }

third_party/blink/renderer/modules/webgpu/gpu_device_lost_info.cc

@@ -9,28 +9,28 @@ namespace blink {
 
 GPUDeviceLostInfo::GPUDeviceLostInfo(const WGPUDeviceLostReason reason,
                                      const String& message) {
-  message_ = message;
   switch (reason) {
+    case WGPUDeviceLostReason_Undefined:
+      reason_ = "unknown";
+      break;
     case WGPUDeviceLostReason_Destroyed:
       reason_ = "destroyed";
       break;
     default:
-      // Leave the reason as null indicating that it is not an expected scenario
-      // for the device to be lost.
+      // If this is hit, Dawn gave us a reason we haven't implemented here yet.
+      NOTREACHED();
+      reason_ = "unknown";
       break;
   }
-}
-
-const String& GPUDeviceLostInfo::message() const {
-  return message_;
+  message_ = message;
 }
 
 const ScriptValue GPUDeviceLostInfo::reason(ScriptState* script_state) const {
-  if (reason_.IsNull()) {
-    v8::Isolate* isolate = script_state->GetIsolate();
-    return ScriptValue(isolate, v8::Undefined(isolate));
-  }
   return ScriptValue::From(script_state, reason_);
 }
 
+const String& GPUDeviceLostInfo::message() const {
+  return message_;
+}
+
 }  // namespace blink

third_party/blink/renderer/modules/webgpu/gpu_device_lost_info.h

@@ -24,12 +24,12 @@ class GPUDeviceLostInfo : public ScriptWrappable {
   GPUDeviceLostInfo& operator=(const GPUDeviceLostInfo&) = delete;
 
   // gpu_device_lost_info.idl
-  const String& message() const;
   const ScriptValue reason(ScriptState* script_state) const;
+  const String& message() const;
 
  private:
-  String message_;
   String reason_;
+  String message_;
 };
 
 }  // namespace blink

third_party/blink/renderer/modules/webgpu/gpu_device_lost_info.idl

@@ -5,18 +5,15 @@
 // https://gpuweb.github.io/gpuweb/
 
 enum GPUDeviceLostReason {
+  "unknown",
   "destroyed"
 };
 
 [
     Exposed(Window WebGPU, DedicatedWorker WebGPU),
     SecureContext
 ] interface GPUDeviceLostInfo {
+    [CallWith=ScriptState] readonly attribute GPUDeviceLostReason reason;
     readonly attribute DOMString message;
-    // TODO: The type should be (GPUDeviceLostReason or undefined) but
-    // the bindings can't handle it now although it should be valid type.
-    // As a workaround we make the type any and do custom handling in Blink
-    // until the bindings supports it. Refer to crbug.com/1293259.
-    [CallWith=ScriptState] readonly attribute any reason;
 };