Fix data race in InspectorInstrumentation::hasFrontends

Source/core/inspector/InspectorInstrumentation.h

 /*
 * Copyright (C) 2010 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 73 matching lines @@
     STATIC_ONLY(FrontendCounter);
 private:
     friend void frontendCreated();
     friend void frontendDeleted();
     friend bool hasFrontends();
     static int s_frontendCounter;
 };
 
 inline void frontendCreated() { atomicIncrement(&FrontendCounter::s_frontendCounter); }
 inline void frontendDeleted() { atomicDecrement(&FrontendCounter::s_frontendCounter); }
-inline bool hasFrontends() { return FrontendCounter::s_frontendCounter; }
+inline bool hasFrontends() { return acquireLoad(&FrontendCounter::s_frontendCounter); }
 
 CORE_EXPORT void registerInstrumentingAgents(InstrumentingAgents*);
 CORE_EXPORT void unregisterInstrumentingAgents(InstrumentingAgents*);
 
 // Called from generated instrumentation code.
 CORE_EXPORT InstrumentingAgents* instrumentingAgentsFor(LocalFrame*);
 InstrumentingAgents* instrumentingAgentsFor(EventTarget*);
 InstrumentingAgents* instrumentingAgentsFor(ExecutionContext*);
 InstrumentingAgents* instrumentingAgentsFor(Document&);
 InstrumentingAgents* instrumentingAgentsFor(Document*);
@@ skipping 68 matching lines @@
 
 } // namespace blink
 
 #include "core/InspectorInstrumentationInl.h"
 
 #include "core/inspector/InspectorInstrumentationCustomInl.h"
 
 #include "core/InspectorOverridesInl.h"
 
 #endif // !defined(InspectorInstrumentation_h)