Compile error on Windows:

error C2561: 'rx::Renderer11::clearTextures' : function must return a value

BUG=angleproject:959

This reverts commit 475e5b7f.

Change-Id: Id34ff9530a71ce43549e2eb78d2d927084d46a47
Reviewed-on: https://chromium-review.googlesource.com/280915Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>