[ABANDONED] Call Microtask::performCheckpoint for each worker task.

Source/bindings/v8/V8PerIsolateData.cpp

Index: Source/bindings/v8/V8PerIsolateData.cpp
diff --git a/Source/bindings/v8/V8PerIsolateData.cpp b/Source/bindings/v8/V8PerIsolateData.cpp
index f9cceceb7ffc7c46e76b34ab90ce6829f63165a2..d08a34c78b526e938308ee4ed49fa11acced75fc 100644
--- a/Source/bindings/v8/V8PerIsolateData.cpp
+++ b/Source/bindings/v8/V8PerIsolateData.cpp
@@ -127,8 +127,14 @@ void V8PerIsolateData::setDOMTemplate(void* domTemplateKey, v8::Handle<v8::Funct
 
 v8::Local<v8::Context> V8PerIsolateData::ensureDomInJSContext()
 {
-    if (!m_blinkInJSScriptState)
-        m_blinkInJSScriptState = NewScriptState::create(v8::Context::New(m_isolate), DOMWrapperWorld::create());
+    if (!m_blinkInJSScriptState) {
+        v8::Local<v8::Context> context(v8::Context::New(m_isolate));
+        if (context.IsEmpty()) {
+            // The script execution has been terminated.
+            return context;
+        }
+        m_blinkInJSScriptState = NewScriptState::create(context, DOMWrapperWorld::create());
+    }
     return m_blinkInJSScriptState->context();
 }