Lift outdated NVIDIA test suppressions

Lift some test suppressions for bugs that have been fixed in the
NVIDIA driver a good while ago.

Also improve code style in some suppressions - prefer IsOSX() and
IsLinux() to using ifdefs.

BUG=angleproject:1305
TEST=angle_end2end_tests

Change-Id: Ia069f5b9696000c901956d2952801d5f5c339a11
Reviewed-on: https://chromium-review.googlesource.com/518168
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
diff --git a/src/tests/gl_tests/GLSLTest.cpp b/src/tests/gl_tests/GLSLTest.cpp
index e254577..95b27e3 100644
--- a/src/tests/gl_tests/GLSLTest.cpp
+++ b/src/tests/gl_tests/GLSLTest.cpp
@@ -1086,8 +1086,9 @@
 // Verify that functions without return statements still compile
 TEST_P(GLSLTest_ES3, MissingReturnStructOfArrays)
 {
-    // TODO(cwallez) remove the suppression once NVIDIA removes the restriction for
-    // GLSL >= 300. It was defined only in GLSL 2.0, section 6.1.
+    // TODO(cwallez) remove the suppression once NVIDIA drivers are updated across trybots, drivers
+    // since late 2016 should have the fix. Last check on 2017-05-30 revealed that the Windows
+    // Server 2008 bots still had the old, failing drivers.
     if (IsNVIDIA() && IsOpenGLES())
     {
         std::cout << "Test skipped on NVIDIA OpenGL ES because it disallows returning "