Revert of [scheduler] Change TaskQueue observer call mechanism.

third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc

 // Copyright 2014 The Chromium 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 "platform/scheduler/renderer/renderer_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/debug/stack_trace.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 852 matching lines @@
   // for it since these tasks are not user-provided work and they are only
   // intended to run before the next task, not interrupt the tasks.
   switch (GetMainThreadOnly().current_use_case) {
     case UseCase::COMPOSITOR_GESTURE:
     case UseCase::NONE:
       return GetMainThreadOnly().touchstart_expected_soon;
 
     case UseCase::MAIN_THREAD_GESTURE:
     case UseCase::MAIN_THREAD_CUSTOM_INPUT_HANDLING:
     case UseCase::SYNCHRONIZED_GESTURE:
-      return compositor_task_queue_->HasTaskToRunImmediately() ||
+      return compositor_task_queue_->HasPendingImmediateWork() ||
              GetMainThreadOnly().touchstart_expected_soon;
 
     case UseCase::TOUCHSTART:
       return true;
 
     case UseCase::LOADING:
       return false;
 
     default:
       NOTREACHED();
@@ skipping 1113 matching lines @@
     case TimeDomainType::VIRTUAL:
       return "virtual";
     default:
       NOTREACHED();
       return nullptr;
   }
 }
 
 }  // namespace scheduler
 }  // namespace blink