IDL: make optional arguments (without default) explicit sometimes

Source/bindings/tests/idls/TestObject.idl

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 392 matching lines @@
     void voidMethodDefaultIntegerArgs(optional long defaultLongArg = 10,
                                       optional long long defaultLongLongArg = -10,
                                       optional unsigned long defaultUnsignedArg = 0xFFFFFFFF);
     void voidMethodDefaultDoubleArg(optional double defaultDoubleArg = 0.5);
     void voidMethodDefaultTrueBooleanArg(optional boolean defaultBooleanArg = true);
     void voidMethodDefaultFalseBooleanArg(optional boolean defaultBooleanArg = false);
     void voidMethodDefaultNullableByteStringArg(optional ByteString? defaultStringArg = null);
     void voidMethodDefaultNullableStringArg(optional DOMString? defaultStringArg = null);
     void voidMethodDefaultNullableTestInterfaceArg(optional TestInterface? defaultTestInterfaceArg = null);
 
+    // Optional argument without default followed by optional argument with default
+    void voidMethodOptionalArgWithoutDefault(optional DOMString optionalStringArg, optional boolean defaultBooleanArg = false);
+
     // Variadic operations
     void voidMethodVariadicStringArg(DOMString... variadicStringArgs);
     void voidMethodStringArgVariadicStringArg(DOMString stringArg, DOMString... variadicStringArgs);
     void voidMethodVariadicTestInterfaceEmptyArg(TestInterfaceEmpty... variadicTestInterfaceEmptyArgs);
     void voidMethodTestInterfaceEmptyArgVariadicTestInterfaceEmptyArg(TestInterfaceEmpty testInterfaceEmptyArg, TestInterfaceEmpty... variadicTestInterfaceEmptyArgs);
     void voidMethodVariadicTestInterfaceGarbageCollectedArg(TestInterfaceGarbageCollected... variadicTestInterfaceGarbageCollectedArg);
     void voidMethodVariadicTestInterfaceWillBeGarbageCollectedArg(TestInterfaceWillBeGarbageCollected... variadicTestInterfaceWillBeGarbageCollectedArg);
 
     // Overloaded methods
     void overloadedMethodA(long longArg);
@@ skipping 21 matching lines @@
     [PerWorldBindings] void overloadedPerWorldBindingsMethod();
     [PerWorldBindings] void overloadedPerWorldBindingsMethod(long longArg);
 
     static void overloadedStaticMethod(long longArg);
     static void overloadedStaticMethod(long longArg1, long longArg2);
 
     // Extended attributes for arguments
     // [Clamp]
     void voidMethodClampUnsignedShortArg([Clamp] unsigned short clampUnsignedShortArg);
     void voidMethodClampUnsignedLongArg([Clamp] unsigned long clampUnsignedLongArg);
-    // [Default]
-    void voidMethodDefaultUndefinedTestInterfaceEmptyArg([Default=Undefined] optional TestInterfaceEmpty defaultUndefinedTestInterfaceEmptyArg);
-    void voidMethodDefaultUndefinedLongArg([Default=Undefined] optional long defaultUndefinedLongArg);
-    void voidMethodDefaultUndefinedStringArg([Default=Undefined] optional DOMString defaultUndefinedStringArg);
     // [EnforceRange]
     void voidMethodEnforceRangeLongArg([EnforceRange] long enforceRangeLongArg);
     // [TreatNullAs], [TreatUndefinedAs]
     void voidMethodTreatNullAsEmptyStringStringArg([TreatNullAs=EmptyString] DOMString treatNullAsEmptyStringStringArg);
     void voidMethodTreatNullAsNullStringStringArg([TreatNullAs=NullString] DOMString treatNullAsNullStringStringArg);
     void voidMethodTreatNullAsNullStringTreatUndefinedAsNullStringStringArg([TreatNullAs=NullString, TreatUndefinedAs=NullString] DOMString treatNullAsNullStringStringArg);
 
     // Extended attributes for methods
     [LogActivity, LogAllWorlds] void activityLoggingAccessForAllWorldsMethod();
     [CallWith=ExecutionContext] void callWithExecutionContextVoidMethod();
@@ skipping 81 matching lines @@
     [ImplementedInPrivateScript] Node nodeMethodWithVariousArgumentsImplementedInPrivateScript(Document document, Node node, short value1, double value2, DOMString string);
     [ImplementedInPrivateScript] readonly attribute short readonlyShortAttribute;
     [ImplementedInPrivateScript] attribute short shortAttribute;
     [ImplementedInPrivateScript] attribute DOMString stringAttribute;
     [ImplementedInPrivateScript] attribute Node nodeAttribute;
     [OnlyExposedToPrivateScript] short methodImplementedInCPPForPrivateScriptOnly(short value1, short value2);
     [OnlyExposedToPrivateScript] attribute DOMString attributeImplementedInCPPForPrivateScriptOnly;
     [ImplementedInPrivateScript, OnlyExposedToPrivateScript] short methodForPrivateScriptOnly(short value1, short value2);
     [ImplementedInPrivateScript, OnlyExposedToPrivateScript] attribute DOMString attributeForPrivateScriptOnly;
 };