Fix ScriptPreprocessor leak in inspector test case of LayoutTest.

Source/core/inspector/InspectorDebuggerAgent.cpp

 /*
  * Copyright (C) 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 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.
@@ skipping 144 matching lines @@
 void InspectorDebuggerAgent::disable()
 {
     m_state->setObject(DebuggerAgentState::javaScriptBreakpoints, JSONObject::create());
     m_state->setLong(DebuggerAgentState::pauseOnExceptionsState, ScriptDebugServer::DontPauseOnExceptions);
     m_state->setString(DebuggerAgentState::skipStackPattern, "");
     m_state->setLong(DebuggerAgentState::asyncCallStackDepth, 0);
     m_instrumentingAgents->setInspectorDebuggerAgent(0);
 
     scriptDebugServer().clearBreakpoints();
     scriptDebugServer().clearCompiledScripts();
+    scriptDebugServer().clearPreprocessor();
     stopListeningScriptDebugServer();
     clear();
 
     if (m_listener)
         m_listener->debuggerWasDisabled();
 
     m_skipAllPauses = false;
 }
 
 bool InspectorDebuggerAgent::enabled()
@@ skipping 1271 matching lines @@
 
 void InspectorDebuggerAgent::trace(Visitor* visitor)
 {
     visitor->trace(m_injectedScriptManager);
     visitor->trace(m_listener);
     InspectorBaseAgent::trace(visitor);
 }
 
 } // namespace blink