Don't require npot extensions in ES3 contexts.

BUG=angleproject:1468

Change-Id: I106f765e59b18de0659c85f31ce3fbac8016de95
Reviewed-on: https://chromium-review.googlesource.com/413329
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/validationES.cpp b/src/libANGLE/validationES.cpp
index eae0c35..96b7789 100644
--- a/src/libANGLE/validationES.cpp
+++ b/src/libANGLE/validationES.cpp
@@ -4240,12 +4240,11 @@
     }
 
     // Non-power of 2 ES2 check
-    if (!context->getExtensions().textureNPOT &&
+    if (context->getClientVersion() < Version(3, 0) && !context->getExtensions().textureNPOT &&
         (!isPow2(static_cast<int>(texture->getWidth(baseTarget, 0))) ||
          !isPow2(static_cast<int>(texture->getHeight(baseTarget, 0)))))
     {
-        ASSERT(context->getClientMajorVersion() <= 2 &&
-               (target == GL_TEXTURE_2D || target == GL_TEXTURE_CUBE_MAP));
+        ASSERT(target == GL_TEXTURE_2D || target == GL_TEXTURE_CUBE_MAP);
         context->handleError(Error(GL_INVALID_OPERATION));
         return false;
     }