Fix shared utilities for remote workloads

- test-invoker: Propagate results in AsyncRAFTestInvoker so
  BenchmarkSuite.runAndRecord receives timing data instead of undefined.
- test-runner: Add null-page fallback in measureAsync so remote workloads
  that pass null for frame/page can still force layout.

Author: issackjohn

resources/shared/test-invoker.mjs

@@ -44,8 +44,8 @@ class AsyncRAFTestInvoker extends TestInvoker {
 
             this._asyncCallback();
             setTimeout(async () => {
-                await this._reportCallback();
-                resolve();
+                const results = await this._reportCallback();
+                resolve(results);
             }, 0);
         };
 

resources/shared/test-runner.mjs

@@ -69,7 +69,13 @@ export class TestRunner {
         const measureAsync = () => {
             // Some browsers don't immediately update the layout for paint.
             // Force the layout here to ensure we're measuring the layout time.
-            this.page.layout();
+            if (this.page) {
+                this.page.layout();
+            } else {
+                const body = document.body;
+                const height = body.getBoundingClientRect().height;
+                body._leakedLayoutValue = height;
+            }
 
             const asyncEndTime = performance.now();
             performance.mark(asyncEndLabel);