Invokes platform specific functionality to allocate a new GC handle.
<p>
<b>IMPORTANT:</b> This method is <em>not</em> part of the public
API for <code>Control</code>. It is marked public only so that it
can be shared within the packages provided by SWT. It is not
available on all platforms, and should never be called from
application code.
</p>
@param data the platform specific GC data
@return the platform specific GC handle
Invokes platform specific functionality to allocate a new GC handle. <p> <b>IMPORTANT:</b> This method is <em>not</em> part of the public API for <code>Control</code>. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code. </p>
@param data the platform specific GC data @return the platform specific GC handle