Update Chrome (for Testing) PIN

Chromium pin updated to 132.0.6816.0

Changed roll to include an undefined check for aggregates that is
required to account for chromium backend changes.

Roll created at https://cr-buildbucket.appspot.com/build/8732234552970489025

Bug: 377200307
Change-Id: I62cc56ce73c66a9f810de632503d5762ac60b017
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/5985373
Reviewed-by: Simon Zünd <[email protected]>
Commit-Queue: Kim-Anh Tran <[email protected]>

Author: ktran

DEPS

@@ -49,7 +49,7 @@ vars = {
   # Chrome version used for tests. It should be regularly updated to
   # match the Canary version listed here:
   # https://googlechromelabs.github.io/chrome-for-testing/last-known-good-versions.json
-  'chrome': '132.0.6811.0',
+  'chrome': '132.0.6812.0',
 
   # 'magic' text to tell depot_tools that git submodules should be accepted but
   # but parity with DEPS file is expected.

front_end/entrypoints/heap_snapshot_worker/HeapSnapshot.ts

@@ -2469,7 +2469,7 @@ export abstract class HeapSnapshot {
 
   private calculateDiffForClass(
       baseAggregate: HeapSnapshotModel.HeapSnapshotModel.AggregateForDiff,
-      aggregate: HeapSnapshotModel.HeapSnapshotModel.Aggregate): HeapSnapshotModel.HeapSnapshotModel.Diff|null {
+      aggregate?: HeapSnapshotModel.HeapSnapshotModel.Aggregate): HeapSnapshotModel.HeapSnapshotModel.Diff|null {
     const baseIds = baseAggregate.ids;
     const baseIndexes = baseAggregate.indexes;
     const baseSelfSizes = baseAggregate.selfSizes;
@@ -2480,7 +2480,7 @@ export abstract class HeapSnapshot {
     let j = 0;
     const l = baseIds.length;
     const m = indexes.length;
-    const diff = new HeapSnapshotModel.HeapSnapshotModel.Diff(aggregate.name);
+    const diff = new HeapSnapshotModel.HeapSnapshotModel.Diff(aggregate ? aggregate.name : '');
 
     const nodeB = this.createNode(indexes[j]);
     while (i < l && j < m) {