[DevTools] Force context creation when runtime is enabled.

third_party/WebKit/Source/core/inspector/PageRuntimeAgent.cpp

 /*
  * Copyright (C) 2011 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 47 matching lines @@
 {
     visitor->trace(m_inspectedFrames);
     InspectorRuntimeAgent::trace(visitor);
 }
 
 void PageRuntimeAgent::enable(ErrorString* errorString)
 {
     if (m_enabled)
         return;
 
+    m_instrumentingAgents->setPageRuntimeAgent(this);
+    if (m_inspectedFrames->root()->loader().stateMachine()->committedFirstRealDocumentLoad())
+        m_inspectedFrames->root()->script().initializeMainWorld();
     InspectorRuntimeAgent::enable(errorString);
 }
 
 void PageRuntimeAgent::disable(ErrorString* errorString)
 {
     if (!m_enabled)
         return;
     InspectorRuntimeAgent::disable(errorString);
+    m_instrumentingAgents->setPageRuntimeAgent(nullptr);
+}
+
+void PageRuntimeAgent::didClearDocumentOfWindowObject(LocalFrame* frame)
+{
+    frame->script().initializeMainWorld();
 }
 
 } // namespace blink