Explicitly dispose of async call chains.

Source/core/inspector/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/V8AsyncCallTracker.h"
 
 #include "bindings/core/v8/V8PerContextData.h"
 #include "core/inspector/AsyncCallChainMap.h"
 #include "platform/heap/Handle.h"
@@ skipping 15 matching lines @@
 class V8AsyncCallTracker::V8ContextAsyncCallChains final : public NoBaseWillBeGarbageCollectedFinalized<V8AsyncCallTracker::V8ContextAsyncCallChains> {
     WTF_MAKE_NONCOPYABLE(V8ContextAsyncCallChains);
 public:
     explicit V8ContextAsyncCallChains(InspectorDebuggerAgent* debuggerAgent)
         : m_v8AsyncCallChains(debuggerAgent)
     {
     }
 
     ~V8ContextAsyncCallChains()
     {
+        ASSERT(m_v8AsyncCallChains.hasBeenDisposed());
+    }
+
+    void dispose()
+    {
         // FIXME: get rid of the dispose method and this class altogether once AsyncCallChainMap is always allocated on C++ heap.
         m_v8AsyncCallChains.dispose();
     }
 
     void trace(Visitor* visitor)
     {
 #if ENABLE(OILPAN)
         visitor->trace(m_v8AsyncCallChains);
 #endif
     }
@@ skipping 27 matching lines @@
 #endif
     InspectorDebuggerAgent::AsyncCallTrackingListener::trace(visitor);
 }
 
 void V8AsyncCallTracker::asyncCallTrackingStateChanged(bool)
 {
 }
 
 void V8AsyncCallTracker::resetAsyncCallChains()
 {
-    for (auto& it : m_contextAsyncCallChainMap)
+    for (auto& it : m_contextAsyncCallChainMap) {
         it.key->removeObserver(this);
+        it.value->dispose();
+    }
     m_contextAsyncCallChainMap.clear();
 }
 
 void V8AsyncCallTracker::willDisposeScriptState(ScriptState* state)
 {
     m_contextAsyncCallChainMap.remove(state);
 }
 
 void V8AsyncCallTracker::didReceiveV8AsyncTaskEvent(ScriptState* state, const String& eventType, const String& eventName, int id)
 {
@@ skipping 28 matching lines @@
     if (V8ContextAsyncCallChains* contextCallChains = m_contextAsyncCallChainMap.get(state)) {
         String taskId = makeV8AsyncTaskUniqueId(eventName, id);
         m_debuggerAgent->setCurrentAsyncCallChain(state->isolate(), contextCallChains->m_v8AsyncCallChains.get(taskId));
         contextCallChains->m_v8AsyncCallChains.remove(taskId);
     } else {
         m_debuggerAgent->setCurrentAsyncCallChain(state->isolate(), nullptr);
     }
 }
 
 } // namespace blink