WebGPURenderer: Add data-engine="three.js ${REVISION}" to <canvas>. (#26544)

examples/jsm/renderers/common/Backend.js

@@ -1,7 +1,7 @@
 let vector2 = null;
 let vector4 = null;
 
-import { Vector2, Vector4 } from 'three';
+import { Vector2, Vector4, REVISION } from 'three';
 
 class Backend {
 
@@ -118,7 +118,12 @@ class Backend {
 
 		if ( domElement === null ) {
 
-			this.domElement = domElement = ( this.parameters.canvas !== undefined ) ? this.parameters.canvas : this.createCanvasElement();
+			domElement = ( this.parameters.canvas !== undefined ) ? this.parameters.canvas : this.createCanvasElement();
+
+			// OffscreenCanvas does not have setAttribute, see #22811
+			if ( 'setAttribute' in domElement ) domElement.setAttribute( 'data-engine', `three.js r${REVISION}` );
+
+			this.domElement = domElement;
 
 		}