2013-01-08  Igor Oliveira  <igor.o@sisa.samsung.com>

        If clCreateContextFromType fails, ComputeContext should not be created
        Issue #57

        Reviewed by Antonio Gomes.

        When creating a ComputeContext instance, ComputeContext::create was leaking
        because it was not handling correctly clCreateContext* creation.
        This patch fixes the wrong behavior implementing error handling in the ComputeContext::create
        method.

        * platform/ComputeContext.cpp:
        (WebCore::ComputeContext::create):