2014-06-20  Shilpa Shri  <shilpa.shri@samsung.com>

        Change exception type expected for enqueueWaitForEvents

        Fixed #532

        enqueueWaitForEvents() should throw INVALID_VALUE if eventWaitList is empty

        Reviewed by Sharath.

        Conformance tests:
        conformance/bindingTesting/queues/cl_commandQueue_enqueueWaitForEvents.html

        * Modules/webcl/WebCLCommandQueue.cpp:
        (WebCore::WebCLCommandQueue::enqueueWaitForEvents):