fix GLU dependency

CreatePlatformGLTestContext_glx.cpp uses GLU (gluCheckExtension),
not Skia.

Change-Id: I815445613c33cd7c902dc52cdca2482e0daab839
Reviewed-on: https://skia-review.googlesource.com/136162
Commit-Queue: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
1 file changed