Revert of Implement async AbortAll for the compiler dispatcher

src/cancelable-task.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/cancelable-task.h"
 
 #include "src/base/platform/platform.h"
 #include "src/isolate.h"
 
 namespace v8 {
@@ skipping 75 matching lines @@
         cancelable_tasks_.erase(current);
       }
     }
     // Wait for already running background tasks.
     if (!cancelable_tasks_.empty()) {
       cancelable_tasks_barrier_.Wait(&mutex_);
     }
   }
 }
 
-CancelableTaskManager::TryAbortResult CancelableTaskManager::TryAbortAll() {
-  // Clean up all cancelable fore- and background tasks. Tasks are canceled on
-  // the way if possible, i.e., if they have not started yet.
-  base::LockGuard<base::Mutex> guard(&mutex_);
-
-  if (cancelable_tasks_.empty()) return kTaskRemoved;
-
-  for (auto it = cancelable_tasks_.begin(); it != cancelable_tasks_.end();) {
-    if (it->second->Cancel()) {
-      it = cancelable_tasks_.erase(it);
-    } else {
-      ++it;
-    }
-  }
-
-  return cancelable_tasks_.empty() ? kTaskAborted : kTaskRunning;
-}
-
 CancelableTask::CancelableTask(Isolate* isolate)
     : CancelableTask(isolate, isolate->cancelable_task_manager()) {}
 
 CancelableTask::CancelableTask(Isolate* isolate, CancelableTaskManager* manager)
     : Cancelable(manager), isolate_(isolate) {}
 
 CancelableIdleTask::CancelableIdleTask(Isolate* isolate)
     : CancelableIdleTask(isolate, isolate->cancelable_task_manager()) {}
 
 CancelableIdleTask::CancelableIdleTask(Isolate* isolate,
                                        CancelableTaskManager* manager)
     : Cancelable(manager), isolate_(isolate) {}
 
 }  // namespace internal
 }  // namespace v8