2013-08-14  Afonso R. Costa Jr.  <afonso.costa@samsung.com>

        Refactor a Layout Test which tests two contexts using the same device.
        Issue #99

        Reviewed by: Andre Loureiro
                     Marcelo Morais

        List of changes:
        - Change the file name to: webcl-test-device-using-multiple-contexts.html
        - Remove WebCLProxy
        - Create two contexts with different kernels (vector_add and vector_mult) and
          test them in a CL device (DEVICE_TYPE_DEFAULT)

        * webcl/tests/webcl-test-device-using-multiple-contexts-expected.txt: Renamed from LayoutTests/webcl/tests/webcl-test-devices-multiple-contexts-expected.txt.
        * webcl/tests/webcl-test-device-using-multiple-contexts.html: Added.
        * webcl/tests/webcl-test-devices-multiple-contexts.html: Removed.