Simplify Blink <-> V8 Microtask queue running protocol

Source/core/dom/Microtask.cpp

Index: Source/core/dom/Microtask.cpp
diff --git a/Source/core/dom/Microtask.cpp b/Source/core/dom/Microtask.cpp
index f7ebc42c2ffdfe6c2a46feb184eeb29b16eb64ef..7eed205751602759eab6e1b581ffb4f48504511e 100644
--- a/Source/core/dom/Microtask.cpp
+++ b/Source/core/dom/Microtask.cpp
@@ -47,14 +47,7 @@ void Microtask::performCheckpoint()
     if (isolateData->recursionLevel() || isolateData->performingMicrotaskCheckpoint())
         return;
     isolateData->setPerformingMicrotaskCheckpoint(true);
-
-    v8::HandleScope handleScope(isolate);
-    v8::Local<v8::Context> context = isolateData->ensureDomInJSContext();
-    if (!context.IsEmpty()) {
-        v8::Context::Scope scope(context);
-        isolate->RunMicrotasks();
-    }
-
+    isolate->RunMicrotasks();
     isolateData->setPerformingMicrotaskCheckpoint(false);
 }