Partially address babylonjs leak

JetStreamDriver.js

@@ -1609,6 +1609,7 @@ class AsyncBenchmark extends DefaultBenchmark {
 
                 performance.measure(iterationMarkLabel, iterationMarkLabel);
 
+                benchmark.postIteration?.(i);
                 ${this.postIterationCode}
 
                 results.push(Math.max(1, end - start));
@@ -2693,7 +2694,7 @@ let BENCHMARKS = [
             BUNDLE: "./workloads/babylonjs/dist/bundle.es5.min.js",
         },
         args: {
-            expectedCacheCommentCount: 23988,
+            expectedCacheCommentCount: 23992,
         },
         tags: ["startup",  "js", "class", "es5", "babylonjs"],
         iterations: 10,
@@ -2708,7 +2709,7 @@ let BENCHMARKS = [
             BUNDLE: "./workloads/babylonjs/dist/bundle.es6.min.js",
         },
         args: {
-            expectedCacheCommentCount: 21222,
+            expectedCacheCommentCount: 21225,
         },
         tags: ["Default",  "js", "startup", "class", "es6", "babylonjs"],
         iterations: 10,

workloads/babylonjs/benchmark/scene.js

@@ -37,6 +37,7 @@ class Benchmark {
     cannonData: null,
     particlesJson: null,
   };
+  sceneDisposer;
 
   constructor(iterationCount) {
     this.iterationCount = iterationCount;
@@ -54,12 +55,13 @@ class Benchmark {
   }
 
   async runIteration() {
-    const {classNames, cameraRotationLength} = await BabylonJSBenchmark.runComplexScene(
+    const {classNames, cameraRotationLength, disposer} = await BabylonJSBenchmark.runComplexScene(
       this.preloaded.fortData,
       this.preloaded.cannonData,
       this.preloaded.particlesJson,
       100
     );
+    this.sceneDisposer = disposer;
     const lastResult = {
       classNames,
       cameraRotationLength
@@ -76,4 +78,10 @@ class Benchmark {
     if (value != expected)
       throw new Error(`Expected ${name} to be ${expected}, but got ${value}`);
   }
+
+  postIteration() {
+    // FIXME: move to measured phase. 
+    this.sceneDisposer();
+  }
 }
+

workloads/babylonjs/benchmark/startup.js

@@ -27,6 +27,7 @@
 
 class Benchmark extends StartupBenchmark {
   iteration = 0;
+  sceneDisposer;
 
   constructor({iterationCount, expectedCacheCommentCount}) {
     super({
@@ -47,7 +48,8 @@ class Benchmark extends StartupBenchmark {
     eval(sourceCode);
     // const runStart = performance.now();
 
-    const { classNames, cameraRotationLength } = BabylonJSBenchmark.runTest(30);
+    const { classNames, cameraRotationLength, disposer} = BabylonJSBenchmark.runTest(30);
+    this.sceneDisposer = disposer;
     const lastResult = {
       classNames,
       cameraRotationLength,
@@ -80,4 +82,9 @@ class Benchmark extends StartupBenchmark {
     if (value != expected)
       throw new Error(`Expected ${name} to be ${expected}, but got ${value}`);
   }
+
+  postIteration() {
+    // FIXME: move to measured phase.
+    this.sceneDisposer();
+  }
 }