Add simple_vertex_shader back to the GYP

Change-Id: I1d078af32c725e7bdd5b366ff8218758049f5a38
Reviewed-on: https://chromium-review.googlesource.com/272065
Tested-by: Austin Kinross <aukinros@microsoft.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

samples/samples.gyp

@@ -177,6 +177,14 @@
             'sources': [ 'simple_texture_cubemap/SimpleTextureCubemap.cpp', ],
         },
 
+        {
+            'target_name': 'simple_vertex_shader',
+            'type': 'executable',
+            'dependencies': [ 'sample_util' ],
+            'includes': [ '../build/common_defines.gypi', ],
+            'sources': [ 'simple_vertex_shader/SimpleVertexShader.cpp', ],
+        },
+
         {
             'target_name': 'stencil_operations',
             'type': 'executable',