This patch enables tracing of vertex attribute data that
is specified using glVertexAttribPointer().
At the time the glVertexAttribPointer() call is made, we
only receive a pointer in client space, without any indication
of the size (# of attributes). This size is known only at
the time of the glDraw() call.
This patch generates a new message glVertexAttribPointerData()
when a draw call is issued that contains the vertex attribute
data.
A glDrawArrays() call directly gives the size of data to copy.
A glDrawElements() call gives the indices to copy. In such a
case, all data between the min & max indices drawn are copied
and sent to the host. To support glDrawElements() with an
element array buffer, this patch also adds state that maintains
a copy of all element array buffers.
Change-Id: I434da794a0aa9ada8e7474e219ffb1d79b183ecf
50129e4ae2