GLES1: Shade model API

+ add sample

BUG=angleproject:2306

Change-Id: Ie0c391618ec2b771cc99b96db02b9008a86272b9
Reviewed-on: https://chromium-review.googlesource.com/1079992
Commit-Queue: Lingfeng Yang <lfy@google.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/Context.cpp b/src/libANGLE/Context.cpp
index 8eb6d9d..e75dcaa 100644
--- a/src/libANGLE/Context.cpp
+++ b/src/libANGLE/Context.cpp
@@ -7091,6 +7091,7 @@
             case GL_POINT_SIZE_ARRAY_STRIDE_OES:
             case GL_POINT_SIZE_ARRAY_TYPE_OES:
             case GL_POINT_SIZE_ARRAY_BUFFER_BINDING_OES:
+            case GL_SHADE_MODEL:
                 *type      = GL_INT;
                 *numParams = 1;
                 return true;