GLES1: gl(Enable|Disable)ClientState

+ Introduce the GL_OES_point_size_array extension for point size array
support.

BUG=angleproject:2306

Change-Id: Ib1a60b7dcd0497eb807f0d3c80bc95b4748d9a96
Reviewed-on: https://chromium-review.googlesource.com/1014282
Commit-Queue: Lingfeng Yang <lfy@google.com>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/libANGLE/validationES2.cpp b/src/libANGLE/validationES2.cpp
index 29f11f5..27d0d3b 100644
--- a/src/libANGLE/validationES2.cpp
+++ b/src/libANGLE/validationES2.cpp
@@ -794,7 +794,14 @@
 
         // GLES1 emulation: GLES1-specific caps
         case GL_ALPHA_TEST:
+        case GL_VERTEX_ARRAY:
+        case GL_NORMAL_ARRAY:
+        case GL_COLOR_ARRAY:
+        case GL_TEXTURE_COORD_ARRAY:
             return context->getClientVersion() < Version(2, 0);
+        case GL_POINT_SIZE_ARRAY_OES:
+            return context->getClientVersion() < Version(2, 0) &&
+                   context->getExtensions().pointSizeArray;
 
         default:
             return false;