2013-09-02  Sharath Kamath  <s.kamath@samsung.com>

        Cache WebCLDevice in platform objects.
        Issue #294

        Reviewed by Antonio.

        Caching devices and type of the devices in WebCLPLatform.
        If an additional query (call to getDevices) happens with a different device type, the cache would be invalidated.
        This will avoid multiple copy of webcl device objects holding reference to same OpenCL object.

        No new tests (OOPS!).

        * Modules/webcl/WebCLPlatform.cpp:
        (WebCore::WebCLPlatform::WebCLPlatform):
        (WebCore::WebCLPlatform::getDevices):
        * Modules/webcl/WebCLPlatform.h: