Clearly determining the GTK toolkit back end implies it's a GTKwebkit. I provided the links so you could check this for yourself.
WebkitGTK is a project to GObjectify/GTKify webkit. Webkit on X11 probably uses (like Firefox) Cairo to draw stuff onto the screen.
Yes this is true, MonoJIT is a Virtual Machine some 2.7 megs in size that relies on calls to native libraries for functionality. Saying Mono does not come with Gstreamer is correct and you can go further and say that if your application using Mono does not have any AV then Gstreamer is not needed. If your application does involve AV then it will require an AV library and codecs. Whose do you use on an Android platform, Microsoft's or Gstreamer? Mono does require Cairo for rendering, Mono requires Glib, Mono requires Freetype and can use the Pango Layout engine, Mono can use Gstreamer for AV. Correct?
Here is a list of what programs mono-core requires on a Fedora 16 system. Can you find Cairo or Glib there?
[tuna@pingu ~]$ yum deplist mono-core
Loaded plugins: langpacks, presto, refresh-packagekit
Finding dependencies:
package: mono-core.i686 2.10.5-1.fc16
dependency: /bin/bash
provider: bash.i686 4.2.20-1.fc16
dependency: /bin/sh
provider: bash.i686 4.2.20-1.fc16
dependency: /usr/bin/env
provider: coreutils.i686 8.12-2.fc16
dependency: ld-linux.so.2
provider: glibc.i686 2.14.90-21
dependency: ld-linux.so.2(GLIBC_2.3)
provider: glibc.i686 2.14.90-21
dependency: libc.so.6(GLIBC_2.11)
provider: glibc.i686 2.14.90-21
dependency: libdl.so.2
provider: glibc.i686 2.14.90-21
dependency: libdl.so.2(GLIBC_2.0)
provider: glibc.i686 2.14.90-21
dependency: libdl.so.2(GLIBC_2.1)
provider: glibc.i686 2.14.90-21
dependency: libgcc_s.so.1
provider: libgcc.i686 4.6.2-1.fc16
provider: AdobeReader_sve.i486 8.1.7-1
provider: AdobeReader_suo.i486 8.1.7-1
provider: AdobeReader_ptb.i486 8.1.7-1
provider: AdobeReader_nor.i486 8.1.7-1
provider: AdobeReader_nld.i486 8.1.7-1
provider: AdobeReader_kor.i486 8.1.7-1
provider: AdobeReader_ita.i486 8.1.7-1
provider: AdobeReader_esp.i486 8.1.7-1
provider: AdobeReader_dan.i486 8.1.7-1
provider: AdobeReader_cht.i486 8.1.7-1
provider: AdobeReader_chs.i486 8.1.7-1
dependency: libgcc_s.so.1(GCC_3.0)
provider: libgcc.i686 4.6.2-1.fc16
provider: AdobeReader_sve.i486 8.1.7-1
provider: AdobeReader_suo.i486 8.1.7-1
provider: AdobeReader_ptb.i486 8.1.7-1
provider: AdobeReader_nor.i486 8.1.7-1
provider: AdobeReader_nld.i486 8.1.7-1
provider: AdobeReader_kor.i486 8.1.7-1
provider: AdobeReader_ita.i486 8.1.7-1
provider: AdobeReader_esp.i486 8.1.7-1
provider: AdobeReader_dan.i486 8.1.7-1
provider: AdobeReader_cht.i486 8.1.7-1
provider: AdobeReader_chs.i486 8.1.7-1
dependency: libgcc_s.so.1(GCC_3.3.1)
provider: libgcc.i686 4.6.2-1.fc16
provider: AdobeReader_sve.i486 8.1.7-1
provider: AdobeReader_suo.i486 8.1.7-1
provider: AdobeReader_ptb.i486 8.1.7-1
provider: AdobeReader_nor.i486 8.1.7-1
provider: AdobeReader_nld.i486 8.1.7-1
provider: AdobeReader_kor.i486 8.1.7-1
provider: AdobeReader_ita.i486 8.1.7-1
provider: AdobeReader_esp.i486 8.1.7-1
provider: AdobeReader_dan.i486 8.1.7-1
provider: AdobeReader_cht.i486 8.1.7-1
provider: AdobeReader_chs.i486 8.1.7-1
dependency: libgcc_s.so.1(GLIBC_2.0)
provider: libgcc.i686 4.6.2-1.fc16
provider: AdobeReader_sve.i486 8.1.7-1
provider: AdobeReader_suo.i486 8.1.7-1
provider: AdobeReader_ptb.i486 8.1.7-1
provider: AdobeReader_nor.i486 8.1.7-1
provider: AdobeReader_nld.i486 8.1.7-1
provider: AdobeReader_kor.i486 8.1.7-1
provider: AdobeReader_ita.i486 8.1.7-1
provider: AdobeReader_esp.i486 8.1.7-1
provider: AdobeReader_dan.i486 8.1.7-1
provider: AdobeReader_cht.i486 8.1.7-1
provider: AdobeReader_chs.i486 8.1.7-1
dependency: libgdiplus
provider: libgdiplus.i686 2.10-2.fc16
dependency: libm.so.6
provider: glibc.i686 2.14.90-21
dependency: libm.so.6(GLIBC_2.0)
provider: glibc.i686 2.14.90-21
dependency: libm.so.6(GLIBC_2.1)
provider: glibc.i686 2.14.90-21
dependency: libpthread.so.0
provider: glibc.i686 2.14.90-21
dependency: libpthread.so.0(GLIBC_2.0)
provider: glibc.i686 2.14.90-21
dependency: libpthread.so.0(GLIBC_2.1)
provider: glibc.i686 2.14.90-21
dependency: libpthread.so.0(GLIBC_2.2)
provider: glibc.i686 2.14.90-21
dependency: libpthread.so.0(GLIBC_2.2.3)
provider: glibc.i686 2.14.90-21
dependency: libpthread.so.0(GLIBC_2.3.2)
provider: glibc.i686 2.14.90-21
dependency: librt.so.1
provider: glibc.i686 2.14.90-21
dependency: librt.so.1(GLIBC_2.2)
provider: glibc.i686 2.14.90-21
dependency: libstdc++.so.6
provider: libstdc++.i686 4.6.2-1.fc16
provider: AdobeReader_sve.i486 8.1.7-1
provider: AdobeReader_suo.i486 8.1.7-1
provider: AdobeReader_ptb.i486 8.1.7-1
provider: AdobeReader_nor.i486 8.1.7-1
provider: AdobeReader_nld.i486 8.1.7-1
provider: AdobeReader_kor.i486 8.1.7-1
provider: AdobeReader_ita.i486 8.1.7-1
provider: AdobeReader_esp.i486 8.1.7-1
provider: AdobeReader_dan.i486 8.1.7-1
provider: AdobeReader_cht.i486 8.1.7-1
provider: AdobeReader_chs.i486 8.1.7-1
dependency: libz.so.1
provider: zlib.i686 1.2.5-5.fc16
dependency: libz.so.1(ZLIB_1.2.3.3)
provider: zlib.i686 1.2.5-5.fc16
dependency: rtld(GNU_HASH)
provider: glibc.i686 2.14.90-21
Also, on Android, maybe you could use the OS codecs/media framework if you want to? Or write your own, or ship GStreamer if that is what you want.
The changes that have occurred in the last 2 years to enable POSIX cross platform support (on hand held platforms for the most part) have impacted Mono, most of the Gnome libraries and Cairo. X11 is out of the picture for obvious reasons, what Google did with Skia on Android not requiring X11 for windowing is what GTK did using Cairo. It reduced the size of the OS with only a minimal loss in functionality. GTK can still use GDK X11 as a backend if that functionality is needed at the cost of a larger OS footprint.
I do not get the point.
For those who don't follow provided Links, the following is a list of the Sony internal libraries listed for the PS3 GTKwebkit disclosure March 2011: Cairo was disclosed at the same time and separate from the GTKwebkit disclosure. Cairo is being used by more than webkit in the PS3.
http://downloads.snei-opensource.com/pub/webkit/webkit-11.02.03-ga52edd9/
Much of this would be off topic but for the fact that any platform with a GTKwebkit can easily support PS Suite.
The abobe link only lists Cairo and Webkit.