https://bugs.webkit.org/show_bug.cgi?id=70215

Reviewed by Adam Barth.

Source/JavaScriptCore:

Added a method that judges if a given JSValue is empty.

Tests: transforms/svg-vs-css.xhtml
       transforms/cssmatrix-2d-interface.xhtml
       transforms/cssmatrix-3d-interface.xhtml

* runtime/JSValue.h:
* runtime/JSValueInlineMethods.h:
(JSC::JSValue::isEmpty):

Source/WebCore:

This patch implements [Optional=CallWithNullValue] IDL for JSC.
While a parameter specified as [Optional=CallWithDefaultValue] is
handled as a string "undefined", a parameter specified as
[Optional=CallWithNullValue] is handled as a null string.
(Note: not a string "null", but a null string).

c.f. [Optional=CallWithNullValue] is implemented in V8 in bug 67458.

Tests: fast/dom/global-constructors.html
       transforms/svg-vs-css.xhtml
       transforms/cssmatrix-2d-interface.xhtml
       transforms/cssmatrix-3d-interface.xhtml

* GNUmakefile.list.am: Removed JSWebKitCSSMatrixCustom.cpp.
* UseJSC.cmake: Ditto.
* WebCore.gypi: Ditto.
* WebCore.pro: Ditto.
* WebCore.xcodeproj/project.pbxproj: Ditto.
* bindings/js/JSBindingsAllInOne.cpp: Ditto.
* bindings/js/JSDOMBinding.h: MAYBE_MISSING_PARAMETER(exec, index, policy) returns the index-th parameter, if the parameter exists. It returns an undefined value, if the index-th parameter is missing and the policy is MissingIsUndefined. It returns an empty value, otherwise (i.e. if the index-th parameter is missing and the policy is MissingIsEmpty).
* bindings/js/JSWebKitCSSMatrixCustom.cpp: Removed.
* bindings/scripts/CodeGeneratorJS.pm:
(GenerateParametersCheck): Supported [Optional=CallWithNullValue].
(GenerateConstructorDefinition): Supported [Optional=CallWithNullValue].
* css/WebKitCSSMatrix.idl: Removed [JSCustomConstructor].


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@98679 268f45cc-cd09-0410-ab3c-d52691b4dbfc