Oilpan: use a cross-thread persistent for per-isolate ScriptDebugServers.

Source/bindings/core/v8/V8PerIsolateData.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 59 matching lines @@
     , m_stringCache(adoptPtr(new StringCache(isolate())))
     , m_hiddenValue(adoptPtr(new V8HiddenValue()))
     , m_constructorMode(ConstructorMode::CreateNewObject)
     , m_recursionLevel(0)
     , m_isHandlingRecursionLevelError(false)
     , m_isReportingException(false)
 #if ENABLE(ASSERT)
     , m_internalScriptRecursionLevel(0)
 #endif
     , m_performingMicrotaskCheckpoint(false)
+    , m_debugServer(nullptr)
 {
     // FIXME: Remove once all v8::Isolate::GetCurrent() calls are gone.
     isolate()->Enter();
 #if ENABLE(ASSERT)
     // currentThread will always be non-null in production, but can be null in Chromium unit tests.
     if (blink::Platform::current()->currentThread())
         isolate()->AddCallCompletedCallback(&assertV8RecursionScope);
 #endif
     if (isMainThread())
         mainThreadPerIsolateData = this;
@@ skipping 44 matching lines @@
 
 void V8PerIsolateData::destroy(v8::Isolate* isolate)
 {
 #if ENABLE(ASSERT)
     if (blink::Platform::current()->currentThread())
         isolate->RemoveCallCompletedCallback(&assertV8RecursionScope);
 #endif
     V8PerIsolateData* data = from(isolate);
     // FIXME: Remove once all v8::Isolate::GetCurrent() calls are gone.
     isolate->Exit();
+    data->m_debugServer.clear();
     delete data;
 }
 
 V8PerIsolateData::DOMTemplateMap& V8PerIsolateData::currentDOMTemplateMap()
 {
     if (DOMWrapperWorld::current(isolate()).isMainWorld())
         return m_domTemplateMapForMainWorld;
     return m_domTemplateMapForNonMainWorld;
 }
 
@@ skipping 110 matching lines @@
     m_endOfScopeTasks.clear();
 }
 
 void V8PerIsolateData::setScriptDebugServer(PassOwnPtrWillBeRawPtr<ScriptDebugServer> server)
 {
     ASSERT(!m_debugServer);
     m_debugServer = server;
 }
 
 } // namespace blink