DevTools [Memory]: Making containment source links context menu accessible

Changes:
 - Added context menu option for "Reveal in Sources Panel" on data grid entries that contain source links

Context menu on entry with source link:
https://imgur.com/PnIQF7z

Context menu on entry without source link:
https://imgur.com/xoNwSIX

Bug: 963183

Change-Id: I4c94ab2d3115704d1a8740b81161633b25b547e1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1717317
Commit-Queue: Michael Liao <michael.liao@microsoft.com>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703871}

third_party/blink/renderer/devtools/front_end/profiler/HeapSnapshotDataGrids.js

@@ -146,6 +146,9 @@ Profiler.HeapSnapshotSortableDataGrid = class extends DataGrid.DataGrid {
     contextMenu.revealSection().appendItem(ls`Reveal in Summary view`, () => {
       this._dataDisplayDelegate.showObject(node.snapshotNodeId, ls`Summary`);
     });
+    if (gridNode.linkElement && !contextMenu.containsTarget(gridNode.linkElement)) {
+      contextMenu.appendApplicableItems(gridNode.linkElement);
+    }
   }
 
   resetSortingCache() {

third_party/blink/renderer/devtools/front_end/profiler/HeapSnapshotGridNodes.js

@@ -616,6 +616,7 @@ Profiler.HeapSnapshotGenericObjectNode = class extends Profiler.HeapSnapshotGrid
     const link = await this._dataGrid.dataDisplayDelegate().linkifyObject(this.snapshotNodeIndex);
     if (link) {
       linkContainer.appendChild(link);
+      this.linkElement = link;
     } else {
       linkContainer.remove();
     }