WebGPURenderer: Introduce waitForGPU (#29686)

* WebGPURenderer: Introduce syncWithGPU

* cleanup

* rename method

* rename to waitForGPU

src/renderers/common/Renderer.js

@@ -398,6 +398,12 @@ class Renderer {
 
 	}
 
+	async waitForGPU() {
+
+		await this.backend.waitForGPU();
+
+	}
+
 	setMRT( mrt ) {
 
 		this._mrt = mrt;

src/renderers/webgl-fallback/WebGLBackend.js

@@ -81,6 +81,11 @@ class WebGLBackend extends Backend {
 
 	}
 
+	async waitForGPU() {
+
+		await this.utils._clientWaitAsync();
+
+	}
 
 	initTimestampQuery( renderContext ) {
 

src/renderers/webgpu/WebGPUBackend.js

@@ -835,6 +835,12 @@ class WebGPUBackend extends Backend {
 
 	}
 
+	async waitForGPU() {
+
+		await this.device.queue.onSubmittedWorkDone();
+
+	}
+
 	// render object
 
 	draw( renderObject, info ) {