DevTools: fix assertion failure when collecting async calls stacks

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 15 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/inspector/InspectorDebuggerAgent.h"
 
 #include "bindings/core/v8/V8Binding.h"
 #include "core/inspector/ScriptAsyncCallStack.h"
 #include "core/inspector/v8/V8Debugger.h"
+#include "platform/ScriptForbiddenScope.h"
+#include "wtf/MainThread.h"
 
 namespace blink {
 
 InspectorDebuggerAgent::InspectorDebuggerAgent(InjectedScriptManager* injectedScriptManager, V8Debugger* debugger, int contextGroupId)
     : InspectorBaseAgent<InspectorDebuggerAgent, InspectorFrontend::Debugger>("Debugger")
     , m_v8DebuggerAgent(adoptPtrWillBeNoop(new V8DebuggerAgent(injectedScriptManager, debugger, this, contextGroupId)))
 {
 }
 
 InspectorDebuggerAgent::~InspectorDebuggerAgent()
@@ skipping 206 matching lines @@
     m_instrumentingAgents->setInspectorDebuggerAgent(nullptr);
 }
 
 bool InspectorDebuggerAgent::isPaused()
 {
     return m_v8DebuggerAgent->isPaused();
 }
 
 PassRefPtrWillBeRawPtr<ScriptAsyncCallStack> InspectorDebuggerAgent::currentAsyncStackTraceForConsole()
 {
+    OwnPtr<ScriptForbiddenScope::AllowUserAgentScript> allowScripting;

[esprehn, 2015/08/19 22:43:53]

I think you want to use Optional<ScriptForbiddenScope::AllowUserAgentScript>
instead.

[yurys, 2015/08/20 00:05:09]

Didn't know that we have Optional, thanks! 
https://codereview.chromium.org/1286383007

+    if (isMainThread())
+        allowScripting = adoptPtr(new ScriptForbiddenScope::AllowUserAgentScript());
     return m_v8DebuggerAgent->currentAsyncStackTraceForConsole();
 }
 
 void InspectorDebuggerAgent::didFireTimer()
 {
     m_v8DebuggerAgent->cancelPauseOnNextStatement();
 }
 
 void InspectorDebuggerAgent::didHandleEvent()
 {
@@ skipping 44 matching lines @@
 {
     m_v8DebuggerAgent->clearFrontend();
 }
 
 void InspectorDebuggerAgent::restore()
 {
     m_v8DebuggerAgent->restore();
 }
 
 } // namespace blink