Specifically, the record EMR_EXTSELECTCLIPRGN specifies the default
clip region if the RegionMode field is set to RGN_COPY.
See EMF specification section 2.3.2.2 available from
http://msdn.microsoft.com/en-us/library/cc230624.aspx

A unit test had to be changed for this - instead of checking for
a specific clip region, it now checks that no clip region is
specified. This is under the assumption that the default clip
region for our device context is "show everything" - i.e. no clip.

Note also that RGN_COPY seems to be a common mode value for this
record type.

Change-Id: I7bd4fe305dda184d121465005fe09d3c113e3063