Add support for khronos gl-cts using its drawElements apis

gpu/khronos_glcts_support/khronos_glcts_gtf.gyp

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  'includes': [
+    'khronos_glcts.gypi',
+  ],
+  'targets': [
+    {
+      'target_name': 'gtf_es',
+      'type': 'static_library',
+      'dependencies': [
+        '<(DEPTH)/gpu/khronos_glcts_support/khronos_glcts_framework.gyp:debase',
+        '<(DEPTH)/gpu/khronos_glcts_support/khronos_glcts_cts.gyp:glcts_gtf_wrapper',
+        '<(DEPTH)/third_party/expat/expat.gyp:expat',
+      ],
+      'include_dirs': [
+        '<(DEPTH)/third_party/khronos_glcts/GTF_ES/glsl/GTF/Source',
+      ],
+      'direct_dependent_settings': {
+        'include_dirs': [
+          '<(DEPTH)/third_party/khronos_glcts/GTF_ES/glsl/GTF/Source',
+        ],
+      },
+      'sources': [
+        '<@(gtf_core_srcs)',
+        '<@(gtf_gl_core_srcs)',
+        '<@(gtf_gles2_srcs)',
+        '<@(gtf_gles2_es_only_srcs)',
+      ],
+    },
+  ],
+}