DevTools: do not enable debugger for pages where script execution is prohibited

Source/core/inspector/PageDebuggerAgent.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 54 matching lines @@
 }
 
 DEFINE_TRACE(PageDebuggerAgent)
 {
     visitor->trace(m_pageScriptDebugServer);
     visitor->trace(m_pageAgent);
     visitor->trace(m_overlay);
     InspectorDebuggerAgent::trace(visitor);
 }
 
-void PageDebuggerAgent::enable()
+bool PageDebuggerAgent::enable()
 {
-    InspectorDebuggerAgent::enable();
-    m_instrumentingAgents->setPageDebuggerAgent(this);
+    bool result = InspectorDebuggerAgent::enable();
+    if (result)
+        m_instrumentingAgents->setPageDebuggerAgent(this);
+    return result;
 }
 
 void PageDebuggerAgent::disable()
 {
     InspectorDebuggerAgent::disable();
     m_instrumentingAgents->setPageDebuggerAgent(0);
 }
 
-void PageDebuggerAgent::startListeningScriptDebugServer()
+bool PageDebuggerAgent::startListeningScriptDebugServer()
 {
-    scriptDebugServer().addListener(this, m_pageAgent->inspectedFrame(), m_debuggerId);
+    return scriptDebugServer().addListener(this, m_pageAgent->inspectedFrame(), m_debuggerId);
 }
 
 void PageDebuggerAgent::stopListeningScriptDebugServer()
 {
     scriptDebugServer().removeListener(this, m_pageAgent->inspectedFrame());
 }
 
 PageScriptDebugServer& PageDebuggerAgent::scriptDebugServer()
 {
     return *m_pageScriptDebugServer;
@@ skipping 51 matching lines @@
         return;
     reset();
 }
 
 void PageDebuggerAgent::didCommitLoadForLocalFrame(LocalFrame*)
 {
     resetModifiedSources();
 }
 
 } // namespace blink