Include extra native bytes in heap snapshot total size

V8 recently started reporting how much Oilpan memory is not represented
in a heap snapshot. This change updates DevTools to include that extra
memory when computing the total size, so that the total size reported
for the snapshot can better match Blink's actual memory usage.

Bug: 40734351
Change-Id: I89e176e164ac73779ef4ced9d52871a1056e0704
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6216979
Commit-Queue: Seth Brenith <[email protected]>
Reviewed-by: Simon Zünd <[email protected]>

Author: sethbrenith

front_end/entrypoints/heap_snapshot_worker/HeapSnapshot.ts

@@ -764,7 +764,7 @@ export abstract class HeapSnapshot {
   #aggregatesSortedFlags: {
     [x: string]: boolean,
   };
-  #profile: Profile;
+  profile: Profile;
   nodeTypeOffset!: number;
   nodeNameOffset!: number;
   nodeIdOffset!: number;
@@ -845,7 +845,7 @@ export abstract class HeapSnapshot {
     this.#aggregates = {};
 
     this.#aggregatesSortedFlags = {};
-    this.#profile = profile;
+    this.profile = profile;
     this.#ignoredNodesInRetainersView = new Set();
     this.#ignoredEdgesInRetainersView = new Set();
     this.#edgeNamesThatAreNotWeakMaps = Platform.TypedArrayUtilities.createBitVector(this.strings.length);
@@ -939,7 +939,7 @@ export abstract class HeapSnapshot {
     this.buildLocationMap();
     this.#progress.updateStatus('Finished processing.');
 
-    if (this.#profile.snapshot.trace_function_count) {
+    if (this.profile.snapshot.trace_function_count) {
       this.#progress.updateStatus('Building allocation statistics…');
       const nodes = this.nodes;
       const nodesLength = nodes.length;
@@ -961,7 +961,7 @@ export abstract class HeapSnapshot {
         stats.size += node.selfSize();
         stats.ids.push(node.id());
       }
-      this.#allocationProfile = new AllocationProfile(this.#profile, liveObjects);
+      this.#allocationProfile = new AllocationProfile(this.profile, liveObjects);
       this.#progress.updateStatus('done');
     }
   }
@@ -1045,7 +1045,7 @@ export abstract class HeapSnapshot {
   }
 
   get totalSize(): number {
-    return this.rootNode().retainedSize();
+    return this.rootNode().retainedSize() + (this.profile.snapshot.extra_native_bytes ?? 0);
   }
 
   private getDominatedIndex(nodeIndex: number): number {
@@ -2755,6 +2755,7 @@ export interface HeapSnapshotHeader {
   edge_count: number;
   trace_function_count: number;
   root_index: number;
+  extra_native_bytes?: number;
   /* eslint-enable @typescript-eslint/naming-convention */
 }
 
@@ -3415,7 +3416,7 @@ export class JSHeapSnapshot extends HeapSnapshot {
     const nodeSlicedStringType = this.nodeSlicedStringType;
     const nodeHiddenType = this.nodeHiddenType;
     const nodeStringType = this.nodeStringType;
-    let sizeNative = 0;
+    let sizeNative = this.profile.snapshot.extra_native_bytes ?? 0;
     let sizeTypedArrays = 0;
     let sizeCode = 0;
     let sizeStrings = 0;

front_end/legacy_test_runner/heap_profiler_test_runner/heap_profiler_test_runner.js

@@ -233,6 +233,7 @@ HeapProfilerTestRunner.createHeapSnapshotMockFactories = function() {
     this.nodeFieldsCount = 7;
     this.nodeTypesMap = {};
     this.nodeTypesArray = [];
+    this.extraNativeBytes = 0;
 
     for (const nodeType in HeapProfilerTestRunner.HeapNode.Type) {
       this.nodeTypesMap[nodeType] = this.nodeTypesArray.length;
@@ -260,7 +261,8 @@ HeapProfilerTestRunner.createHeapSnapshotMockFactories = function() {
             node_types: [this.nodeTypesArray, 'string', 'number', 'number', 'number', 'number', 'number'],
             edge_fields: ['type', 'name_or_index', 'to_node'],
             edge_types: [this.edgeTypesArray, 'string_or_number', 'node']
-          }
+          },
+          extra_native_bytes: this.extraNativeBytes
         },
 
         nodes: [],