Set the scissor from OpenGLRenderer::drawColorRects

Bug #8131254

This method is used as an optimization for paths containing only
non-overlapping rectangles. The implementation was correctly
rejecting rectangles invidually but not the bounds of the array
of rectangles. If quickReject() is not called, setupDraw() won't
be able to properly set the scissor.

Change-Id: I50aa11a4bd8b525b267d36a3039fe7a6fba50518