[Libreoffice] [BUG 32598] How to access the current document from a MediaWindow?

Hello, all! I am Skyler Hawthorne, and I am a student hoping to work 
with LibreOffice on this year's Summer of Code. I am working on a BS in 
Computer Science, currently finishing up my lower division courses at a 
community college before I transfer to California State University, 
Northridge. My nickname on the IRC channel is "cosmopolitan".

Now that introduction is out of the way, I was hoping someone could help 
me with a bug! As per the LO GSoC Wiki ( 
http://wiki.documentfoundation.org/Development/GSoc ), I am working on 
an EasyHack bug. I chose Bug #32598 ( 
https://bugs.freedesktop.org/show_bug.cgi?id=32598 ).

I assume that there is some function called something like 
"setChanged()" or something to that effect that just needs to be added 
to the code that controls the video. Using opengrok, I found that 
"mediawindow.cxx" appears to control Mute and Repeat with its 
"setMute()" and "setPlayBackLoop()" functions, respectively.

From here, I was just going to add the call to the function that 
broadcasts the document's modification, but I don't see any 
"getSdDrawDocument()" function, or any other that grabs the current 
document. MediaWindow does not inherit anything, and I've been unable to 
find the function on opengrok, so I've run out of places to look.

Can someone help me find the function that returns the current document? 
And for those knowledgeable, would my proposed fix be sufficient?

Thanks in advance

--
Skyler Hawthorne
a.k.a. Cosmopolitan