Avoid fetching infinite DOM subtrees to prevent crashing

Fixed: 451651659
Change-Id: I41f6c991a1162be49fbefab5be82c2d66dfe4097
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/7105642
Reviewed-by: Alex Rudenko <[email protected]>
Commit-Queue: Alex Rudenko <[email protected]>
Auto-Submit: Philip Pfaffe <[email protected]>

Author: pfaffe

front_end/core/sdk/DOMModel.ts

@@ -632,6 +632,7 @@ export class DOMNode {
   }
 
   async getSubtree(depth: number, pierce: boolean): Promise<DOMNode[]|null> {
+    console.assert(depth > 0, 'Do not fetch an infinite subtree to avoid crashing the renderer for large documents');
     const response = await this.#agent.invoke_requestChildNodes({nodeId: this.id, depth, pierce});
     return response.getError() ? null : this.childrenInternal;
   }

front_end/panels/elements/ElementsTreeElement.ts

@@ -735,7 +735,7 @@ export class ElementsTreeElement extends UI.TreeOutline.TreeElement {
   }
 
   override async expandRecursively(): Promise<void> {
-    await this.nodeInternal.getSubtree(-1, true);
+    await this.nodeInternal.getSubtree(100, true);
     await super.expandRecursively(Number.MAX_VALUE);
   }