Skip clip flush in _texture_2d_copy_from_framebuffer
Skip clip flush in _texture_2d_copy_from_framebuffer

Although there was a comment in cogl_texture_2d_copy_from_framebuffer
explaining that we shouldn't flush the clip state, the comment was a bit
miss-leading implying we were going to explicitly set a NULL clip. Also
we weren't actually avoiding flushing the clip state since we were
passing 0 for the CoglDrawFlags.

We now pass COGL_FRAMEBUFFER_FLUSH_SKIP_CLIP_STATE in to the flags when
flushing the framebuffer state and the comment has be updated to explain
that clipping won't affect reading from the framebuffer so we don't need
to flush it.

Reviewed-by: Neil Roberts <822ec91a7ef82248fd36162ca8ac3283eba70848@linux.intel.com>

Distrotech/cogl,Distrotech/cogl,djdeath/cogl,gcampax/cogl,gcampax/cogl,djdeath/cogl-android,djdeath/cogl-android,Distrotech/cogl,collects/cogl,djdeath/cogl,gcampax/cogl,djdeath/cogl-android,gcampax/cogl,djdeath/cogl,collects/cogl,Distrotech/cogl