Add a public cogl_framebuffer_read_pixels_into_bitmap

This adds a public function to read pixels from a framebuffer into a
CoglBitmap. This replaces the internal function
_cogl_read_pixels_with_rowstride because a CoglBitmap contains a
rowstride so it can be used for the same purpose. A CoglBitmap already
has public API to make one that points to a CoglPixelBuffer so this
function can be used to read pixels into a PBO. It also avoids the
need to push the framebuffer on to the context's stack so it provides
a function which can be used in the 2.0 API after the stack is
removed.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

cogl/cogl-framebuffer-private.h

@@ -244,14 +244,6 @@ _cogl_framebuffer_flush_journal (CoglFramebuffer *framebuffer);
 void
 _cogl_framebuffer_flush_dependency_journals (CoglFramebuffer *framebuffer);
 
-gboolean
-_cogl_framebuffer_try_fast_read_pixel (CoglFramebuffer *framebuffer,
-                                       int x,
-                                       int y,
-                                       CoglReadPixelsFlags source,
-                                       CoglPixelFormat format,
-                                       guint8 *pixel);
-
 void
 _cogl_framebuffer_flush_state (CoglFramebuffer *draw_buffer,
                                CoglFramebuffer *read_buffer,