Treat null dictionary members as missing per WebIDL

third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp

Index: third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp
diff --git a/third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp b/third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp
index 582143235bf88728b212248b0e8797df57bb6a9a..cc25803abfd1d152068722fab8a8a893ff277b79 100644
--- a/third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp
+++ b/third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp
@@ -51,24 +51,20 @@ void {{v8_class}}::toImpl(v8::Isolate* isolate, v8::Local<v8::Value> v8Value, {{
         exceptionState.rethrowV8Exception(block.Exception());
         return;
     }
-    if ({{member.name}}Value.IsEmpty() || {{member.name}}Value->IsUndefined()) {
+    if (isUndefinedOrNull({{member.name}}Value)) {
         {% if member.is_required %}
         exceptionState.throwTypeError("required member {{member.name}} is undefined.");
         return;
         {% else %}
         // Do nothing.
         {% endif %}
-    {% if member.is_nullable %}
-    } else if ({{member.name}}Value->IsNull()) {
-        impl.{{member.null_setter_name}}();
-    {% endif %}
     } else {
         {% if member.deprecate_as %}
         Deprecation::countDeprecationIfNotPrivateScript(isolate, currentExecutionContext(isolate), UseCounter::{{member.deprecate_as}});
         {% endif %}
         {{v8_value_to_local_cpp_value(member) | indent(8)}}
         {% if member.is_interface_type %}
-        if (!{{member.name}} && !{{member.name}}Value->IsNull()) {
+        if (!{{member.name}}) {
             exceptionState.throwTypeError("member {{member.name}} is not of type {{member.idl_type}}.");
             return;
         }