Lift outdated NVIDIA test suppressions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/ClearTest.cpp b/src/tests/gl_tests/ClearTest.cpp
index 1e95ed4..1ad240c 100644
--- a/src/tests/gl_tests/ClearTest.cpp
+++ b/src/tests/gl_tests/ClearTest.cpp
@@ -355,9 +355,11 @@
 // flush or finish after ClearBufferfv or each draw.
 TEST_P(ClearTestES3, RepeatedClear)
 {
-    if (IsD3D11() && (IsNVIDIA() || IsIntel()))
+    if (IsD3D11() && IsIntel())
     {
-        std::cout << "Test skipped on Nvidia and Intel D3D11." << std::endl;
+        // Note that there's been a bug affecting this test on NVIDIA drivers as well, until fall
+        // 2016 driver releases.
+        std::cout << "Test skipped on Intel D3D11." << std::endl;
         return;
     }