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

Source/core/inspector/PageDebuggerAgent.cpp

Index: Source/core/inspector/PageDebuggerAgent.cpp
diff --git a/Source/core/inspector/PageDebuggerAgent.cpp b/Source/core/inspector/PageDebuggerAgent.cpp
index f0adbadeb2bb12da4df928bea1dd823eb514652c..5b0fdb0e227553c0b96af56688e45f12bfdf6672 100644
--- a/Source/core/inspector/PageDebuggerAgent.cpp
+++ b/Source/core/inspector/PageDebuggerAgent.cpp
@@ -72,10 +72,12 @@ DEFINE_TRACE(PageDebuggerAgent)
     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()
@@ -84,9 +86,9 @@ void PageDebuggerAgent::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()