fix texture size check in WindowSurfaceCGL::swap

BUG=angleproject:1233

Change-Id: I92fddf331fe0687b290606fe222863bd0fcbc2da
Reviewed-on: https://chromium-review.googlesource.com/329804
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index b0aa620..bd394b5 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -85,6 +85,7 @@
 Jacek Caban
 Tibor den Ouden
 Régis Fénéon
+Sebastian Bergstein
 
 Microsoft Corporation
  Cooper Partin