[heap-profiler] Fix highlighting of detached DOM tree nodes.

The _markDetachedDOMTreeNodes in the worker sets the detachedDOMTreeNode
flag if the node is native and its name starts with "Detached " prefix.

This patch also ensures that '.highlight' and '.detached-dom-tree-node'
CSS styles are not set both at the same time.

Bug: 811925
Change-Id: Iee4ee0647abb19a36c1be2f078b4c2915d67cba5
Reviewed-on: https://chromium-review.googlesource.com/964761
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Alexei Filippov <alph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544327}

third_party/WebKit/Source/devtools/front_end/heap_snapshot_worker/HeapSnapshot.js

@@ -2616,26 +2616,20 @@ HeapSnapshotWorker.JSHeapSnapshot = class extends HeapSnapshotWorker.HeapSnapsho
   }
 
   _markDetachedDOMTreeNodes() {
+    const nodes = this.nodes;
+    const nodesLength = nodes.length;
+    const nodeFieldCount = this._nodeFieldCount;
+    const nodeNativeType = this._nodeNativeType;
+    const nodeTypeOffset = this._nodeTypeOffset;
     const flag = this._nodeFlags.detachedDOMTreeNode;
-    let detachedDOMTreesRoot;
-    for (let iter = this.rootNode().edges(); iter.hasNext(); iter.next()) {
-      const node = iter.edge.node();
-      if (node.name() === '(Detached DOM trees)') {
-        detachedDOMTreesRoot = node;
-        break;
-      }
-    }
-
-    if (!detachedDOMTreesRoot)
-      return;
-
-    const detachedDOMTreeRE = /^Detached DOM tree/;
-    for (let iter = detachedDOMTreesRoot.edges(); iter.hasNext(); iter.next()) {
-      const node = iter.edge.node();
-      if (detachedDOMTreeRE.test(node.className())) {
-        for (let edgesIter = node.edges(); edgesIter.hasNext(); edgesIter.next())
-          this._flags[edgesIter.edge.node().nodeIndex / this._nodeFieldCount] |= flag;
-      }
+    const node = this.rootNode();
+    for (let nodeIndex = 0, ordinal = 0; nodeIndex < nodesLength; nodeIndex += nodeFieldCount, ordinal++) {
+      const nodeType = nodes[nodeIndex + nodeTypeOffset];
+      if (nodeType !== nodeNativeType)
+        continue;
+      node.nodeIndex = nodeIndex;
+      if (node.name().startsWith('Detached '))
+        this._flags[ordinal] |= flag;
     }
   }
 

third_party/WebKit/Source/devtools/front_end/profiler/HeapSnapshotGridNodes.js

@@ -549,7 +549,7 @@ Profiler.HeapSnapshotGenericObjectNode = class extends Profiler.HeapSnapshotGrid
         value = (value || '') + '[]';
         break;
     }
-    if (this._reachableFromWindow)
+    if (this._reachableFromWindow && !this.detachedDOMTreeNode)
       valueStyle += ' highlight';
     if (value === 'Object')
       value = '';