Make [TypeChecking=Interface] the default

third_party/WebKit/Source/core/events/MutationEvent.idl

Index: third_party/WebKit/Source/core/events/MutationEvent.idl
diff --git a/third_party/WebKit/Source/core/events/MutationEvent.idl b/third_party/WebKit/Source/core/events/MutationEvent.idl
index 03ef8302f2b3b05f75073b738e3f5d549ea81d91..9a6e0897ed2a764f111487aed1ee266485657b96 100644
--- a/third_party/WebKit/Source/core/events/MutationEvent.idl
+++ b/third_party/WebKit/Source/core/events/MutationEvent.idl
@@ -31,12 +31,12 @@ interface MutationEvent : Event {
     readonly attribute DOMString      attrName;
     readonly attribute unsigned short attrChange;
     // TODO(philipj): None of the initMutationEvent() arguments should be optional.
-    [Measure] void initMutationEvent([Default=Undefined] optional DOMString type,
-                                     [Default=Undefined] optional boolean bubbles,
-                                     [Default=Undefined] optional boolean cancelable,
-                                     [Default=Undefined] optional Node relatedNode,
-                                     [Default=Undefined] optional DOMString prevValue,
-                                     [Default=Undefined] optional DOMString newValue,
-                                     [Default=Undefined] optional DOMString attrName,
-                                     [Default=Undefined] optional unsigned short attrChange);
+    [Measure, LegacyInterfaceTypeChecking] void initMutationEvent([Default=Undefined] optional DOMString type,
+                                                                  [Default=Undefined] optional boolean bubbles,
+                                                                  [Default=Undefined] optional boolean cancelable,
+                                                                  [Default=Undefined] optional Node relatedNode,
+                                                                  [Default=Undefined] optional DOMString prevValue,
+                                                                  [Default=Undefined] optional DOMString newValue,
+                                                                  [Default=Undefined] optional DOMString attrName,
+                                                                  [Default=Undefined] optional unsigned short attrChange);
 };