2013-12-23 Sharath Kamath <s.kamath@samsung.com>
        Update "Writing to WebCLBuffer" API set to support HTMLCanvasElement.

        Issue #377

        Reviewed by Antonio.

        Conformance test cases:
        [https://github.com/SRA-SiliconValley/webkit-webcl-conformance]
        conformance/extension/WEBCL_html_image/cl_commandQueue_enqueueWriteBufferRect_with_*.html
        conformance/extension/WEBCL_html_image/cl_commandQueue_enqueueWriteBuffer_with_*.html

        Covers the changes to ::
        1. Match existing enqueueWriteBuffer as per specification.
        2. Add support for Writing to buffer from HTMLCanvasElement, HTMLImageElement & imageData.

        * Modules/webcl/WebCLCommandQueue.cpp:
        (WebCore::WebCLCommandQueue::enqueueWriteBuffer):
        (WebCore::WebCLCommandQueue::enqueueWriteBufferRectBase):
        (WebCore::WebCLCommandQueue::enqueueWriteBufferRect):
        (WebCore::WebCLCommandQueue::enqueueReadBuffer):
        (WebCore::WebCLCommandQueue::enqueueReadImage):
        (WebCore::WebCLCommandQueue::enqueueReadBufferRect):
        * Modules/webcl/WebCLCommandQueue.h:
        * Modules/webcl/WebCLCommandQueue.idl:
        * Modules/webcl/WebCLContext.cpp:
        (WebCore::WebCLContext::createBuffer):
        (WebCore::WebCLContext::createImage):
        * Modules/webcl/WebCLHTMLInterop.cpp:
        (WebCore::WebCLHTMLInterop::extractDataFromImage):
        * Modules/webcl/WebCLHTMLInterop.h:
Update read me