Refactor VAO entry points.

This also touches the extension EPs for ES2.

BUG=angleproject:747

Change-Id: Iaa04d97465e518f6b0496e64bc7a737914709b8f
Reviewed-on: https://chromium-review.googlesource.com/637124
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libANGLE/validationES3.cpp b/src/libANGLE/validationES3.cpp
index d015b76..4463108 100644
--- a/src/libANGLE/validationES3.cpp
+++ b/src/libANGLE/validationES3.cpp
@@ -1398,11 +1398,11 @@
     return ValidateBindVertexArrayBase(context, array);
 }
 
-bool ValidateIsVertexArray(Context *context)
+bool ValidateIsVertexArray(Context *context, GLuint array)
 {
     if (context->getClientMajorVersion() < 3)
     {
-        context->handleError(InvalidOperation());
+        ANGLE_VALIDATION_ERR(context, InvalidOperation(), ES3Required);
         return false;
     }