Expose CHROMIUM_texture_mailbox/sync_point stubs in mojo public headers

mojo/public/platform/native/gles2_impl_thunks.cc

Index: mojo/public/platform/native/gles2_impl_thunks.cc
diff --git a/mojo/public/platform/native/gles2_impl_thunks.cc b/mojo/public/platform/native/gles2_impl_thunks.cc
new file mode 100644
index 0000000000000000000000000000000000000000..66dbc396cab152d59148b82d293fdbdea5ba6c85
--- /dev/null
+++ b/mojo/public/platform/native/gles2_impl_thunks.cc
@@ -0,0 +1,29 @@
+// 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.
+
+#include "mojo/public/platform/native/gles2_impl_thunks.h"
+
+#include <assert.h>
+
+#include "mojo/public/platform/native/thunk_export.h"
+
+extern "C" {
+static MojoGLES2ImplThunks g_impl_thunks = {0};
+
+#define VISIT_GL_CALL(Function, ReturnType, PARAMETERS, ARGUMENTS) \
+  ReturnType gl##Function PARAMETERS {                             \
+    assert(g_impl_thunks.Function);                                \
+    return g_impl_thunks.Function ARGUMENTS;                       \
+  }
+#include "mojo/public/c/gles2/gles2_call_visitor_autogen.h"
+#undef VISIT_GL_CALL
+
+extern "C" THUNK_EXPORT size_t
+MojoSetGLES2ImplThunks(const MojoGLES2ImplThunks* gles2_impl_thunks) {
+  if (gles2_impl_thunks->size >= sizeof(g_impl_thunks))
+    g_impl_thunks = *gles2_impl_thunks;
+  return sizeof(g_impl_thunks);
+}
+
+}  // extern "C"