Describe what you were doing when the bug occurred:
1. Clicking back to go back through the frames following a profile session. I think I got to zero and then clicked it again and then it errored

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DevTools version: 4.8.2-fed4ae024

Call stack: at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17661:26)
    at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17710:30)
    at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17710:30)
    at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17710:30)
    at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17710:30)
    at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17710:30)
    at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17710:30)
    at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17710:30)
    at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17710:30)
    at getCommitTree (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:17710:30)

Component stack: at CommitRankedAutoSizer (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:31963:48)
    at div
    at div
    at div
    at SettingsModalContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:26139:23)
    at Profiler_Profiler (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:33363:48)
    at ErrorBoundary (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:27172:5)
    at PortaledContent (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:27303:32)
    at div
    at div
    at ProfilerContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:30463:23)
    at TreeContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:22538:23)
    at SettingsContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:23040:27)
    at ModalDialogContextController (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:28328:23)
    at DevTools_DevTools (chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/build/main.js:33797:21)
if (__DEBUG__) {
              debug('Remove', `fiber ${id} from parent ${parentID}`);
            }
            parentNode.children = parentNode.children.filter(
              childID => childID !== id,
            );
          }
        }
        break;
      }
      case TREE_OPERATION_REMOVE_ROOT: {
        throw Error('Operation REMOVE_ROOT is not supported while profiling.');
      }
      case TREE_OPERATION_REORDER_CHILDREN: {
        id = ((operations[i + 1]: any): number);
        const numChildren = ((operations[i + 2]: any): number);
        const children = ((operations.slice(
          i + 3,
          i + 3 + numChildren,
        ): any): Array<number>);
        i = i + 3 + numChildren;
        if (__DEBUG__) {
          debug('Re-order', `fiber ${id} children ${children.join(',')}`);
        }
        const node = getClonedNode(id);
        node.children = Array.from(children);
        break;
      }
      case TREE_OPERATION_UPDATE_TREE_BASE_DURATION: {
        id = operations[i + 1];