Temorarily comment out NOTREACHED in task manager.

chrome/browser/task_management/providers/child_process_task_provider.cc

Index: chrome/browser/task_management/providers/child_process_task_provider.cc
diff --git a/chrome/browser/task_management/providers/child_process_task_provider.cc b/chrome/browser/task_management/providers/child_process_task_provider.cc
index 884310b9359583dbd28f27315ca697ad2f6d1539..3eee3d393362a54e4901ce91226e904d02240769 100644
--- a/chrome/browser/task_management/providers/child_process_task_provider.cc
+++ b/chrome/browser/task_management/providers/child_process_task_provider.cc
@@ -144,7 +144,10 @@ void ChildProcessTaskProvider::DeleteTask(base::ProcessHandle handle) {
   // processes and are notified (on the UI thread) that the collection is
   // completed at |ChildProcessDataCollected()|.
   if (itr == tasks_by_handle_.end()) {
-    NOTREACHED();
+    // BUG(crbug.com/611067): Temporarily removing due to test flakes. The
+    // reason why this happens is well understood (see bug), but there's no
+    // quick and easy fix.
+    // NOTREACHED();
     return;
   }