Bugzilla

e10s scenario:
1. An DOM element request fulscreen mode.
2. The request is redirected to the parent.
3. Parent enters fullscreen.
4. Parent notifies child that it has finished entering fullscreen.
5. Child goes fullscreen.
6. Then, child notifies parent that it has finished transitionning to fullscreen.
4. Finally, parent notify observers that fullscreen paint has finished.

Let's go into the details of how step 5 works in the above scenario.
5.a The element that made the request is set to fullscreen.
5.b Then, the document where that element lives is set to fullscreen as well as all its ancestors until we reach the top level document. (see Document::ApplyFulscreen method)

Now in Fission world, we may have a request comming from an oop iframe. And it that case since we won't have  to ancestor documents living in different content process(es), we will first notiy those content processes (one after the other from bottom to top) to go fullscreen. Once they all do, the content process where the request originated will be told to enter fullscreen.

e10s scenario:
1. A DOM element request fullscreen mode.
2. The request is redirected to the parent.
3. Parent enters fullscreen.
4. Parent notifies child that it has finished entering fullscreen.
5. Child goes fullscreen.
6. Then, child notifies parent that it has finished transitioning to fullscreen.
7. Finally, parent notifies observers that fullscreen paint has finished.

Let's go into the details of how step 5 works in the above scenario.
5.a The element that made the request is set to fullscreen.
5.b Then, the document where that element lives is set to fullscreen as well as all of its ancestors until we reach the top-level document. (see Document::ApplyFulscreen method)

Now in Fission world, we may have a request coming from an oop iframe. And it that case since we won't be able to directly access to ancestor documents living in different content processes anymore, we will first notify those content processes (one after the other from bottom to top) to go fullscreen. Once they all do, the content process where the request originated from will be told to enter fullscreen. And then the process continues to step 6...