SF: Revert one line that changed in moving doComposeSurfaces

In 688abd45 I included a one line change
to use the display frame instead of the display scissor rectangle when
setting up the client composition display settings for GPU rendering.

This simply reverts that line back to the original value while
preserving the rest of the moved code.

Test: Watched a full-screen video on a Walleye
Bug: 139404471
Change-Id: I3d7165864d5ea4bb9a5538d047c7e3cf0d4b9a50