Delay DOM mutation events in HTMLSelectElement::setOption().

third_party/WebKit/Source/core/html/HTMLSelectElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLSelectElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLSelectElement.cpp b/third_party/WebKit/Source/core/html/HTMLSelectElement.cpp
index 271a9d84cedf1ffc61b0d23912f1481b92152030..7ca8bc148263b660afa5d064085642e28925c4a2 100644
--- a/third_party/WebKit/Source/core/html/HTMLSelectElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLSelectElement.cpp
@@ -429,12 +429,13 @@ void HTMLSelectElement::setOption(unsigned index, HTMLOptionElement* option, Exc
         before.setHTMLElement(options()->item(index + 1));
         remove(index);
     }
+    if (exceptionState.hadException())
+        return;
     // Finally add the new element.
-    if (!exceptionState.hadException()) {
-        add(element, before, exceptionState);
-        if (diff >= 0 && option->selected())
-            optionSelectionStateChanged(option, true);
-    }
+    EventQueueScope scope;
+    add(element, before, exceptionState);
+    if (diff >= 0 && option->selected())
+        optionSelectionStateChanged(option, true);
 }
 
 void HTMLSelectElement::setLength(unsigned newLen, ExceptionState& exceptionState)