Add basic GL functionality to the passthrough command buffer.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 2b29cd1753fe84063a56c6a57831a26d3b31ef8f..14b042bcbfa363602e15310b863fb92346d6fb18 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -139,14 +139,6 @@ GLuint GetServiceId(const OBJECT_TYPE* object) {
   return object ? object->service_id() : 0;
 }
 
-bool CheckUniqueAndNonNullIds(GLsizei n, const GLuint* client_ids) {
-  if (n <= 0)
-    return true;
-  std::unordered_set<uint32_t> unique_ids(client_ids, client_ids + n);
-  return (unique_ids.size() == static_cast<size_t>(n)) &&
-         (unique_ids.find(0) == unique_ids.end());
-}
-
 struct Vec4f {
   explicit Vec4f(const Vec4& data) {
     data.GetValues(v);