TRAC #11134
Takes viewport/scissor dimensions from surface at first makeCurrent, rather
than from display at context construction.

Author:    Shannon Woods
Signed-off-by: Nicolas Capens
Signed-off-by: Daniel Koch

git-svn-id: https://angleproject.googlecode.com/svn/trunk@58 736b8ea6-26fd-11df-bfd4-992fa37f6226