2014-01-21  Sharath Kamath  <s.kamath@samsung.com>

        Enable WEBCL_html_image extension.

        Issue #414

        Reviewed by Antonio.

        Conformance test cases:
        [https://github.com/SRA-SiliconValley/webkit-webcl-conformance]
        All test cases under "WEBCL_html_image" extension.

        * Modules/webcl/WebCLExtensionsAccessor.cpp:
        (WebCore::::enableExtension):
        (WebCore::::getSupportedExtensions):