Oilpan: fix build after r351269.

third_party/WebKit/Source/core/inspector/v8/V8AsyncCallTracker.cpp

 // 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 "config.h"
 #include "core/inspector/v8/V8AsyncCallTracker.h"
 
 #include "bindings/core/v8/V8PerContextData.h"
 #include "core/inspector/AsyncOperationMap.h"
 #include "platform/heap/Handle.h"
@@ skipping 56 matching lines @@
 
 V8AsyncCallTracker::~V8AsyncCallTracker()
 {
     ASSERT(m_contextAsyncOperationMap.isEmpty());
 }
 
 DEFINE_TRACE(V8AsyncCallTracker)
 {
 #if ENABLE(OILPAN)
     visitor->trace(m_contextAsyncOperationMap);
-    visitor->trace(m_debuggerAgent);
 #endif
 }
 
 void V8AsyncCallTracker::asyncCallTrackingStateChanged(bool)
 {
 }
 
 void V8AsyncCallTracker::resetAsyncOperations()
 {
     for (auto& it : m_contextAsyncOperationMap) {
@@ skipping 41 matching lines @@
     if (V8ContextAsyncOperations* contextCallChains = m_contextAsyncOperationMap.get(state)) {
         String taskId = makeV8AsyncTaskUniqueId(eventName, id);
         m_debuggerAgent->traceAsyncCallbackStarting(contextCallChains->m_v8AsyncOperations.get(taskId));
         contextCallChains->m_v8AsyncOperations.remove(taskId);
     } else {
         m_debuggerAgent->traceAsyncCallbackStarting(V8DebuggerAgentImpl::unknownAsyncOperationId);
     }
 }
 
 } // namespace blink