mojo/gpu: Remove dead gpu code.

mojo/gpu/BUILD.gn

Index: mojo/gpu/BUILD.gn
diff --git a/mojo/gpu/BUILD.gn b/mojo/gpu/BUILD.gn
deleted file mode 100644
index ad372388a64363cb6d51e80eb9deaf2ff976e9af..0000000000000000000000000000000000000000
--- a/mojo/gpu/BUILD.gn
+++ /dev/null
@@ -1,18 +0,0 @@
-# Copyright 2015 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.
-
-source_set("mojo_gles2_implementation") {
-  sources = [
-    "mojo_gles2_impl_autogen.cc",
-    "mojo_gles2_impl_autogen.h",
-  ]
-
-  configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
-
-  deps = [
-    "//base",
-    "//gpu/command_buffer/client:gles2_interface",
-    "//mojo/public/c/gles2",
-  ]
-}