Implement debug marker entry points in the passthrough command buffer.

gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc

 // Copyright (c) 2016 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 "gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h"
 
 #include "base/strings/string_number_conversions.h"
 #include "ui/gl/gl_version_info.h"
 
 namespace gpu {
@@ skipping 2480 matching lines @@
 
 error::Error GLES2DecoderPassthroughImpl::DoSetDisjointValueSyncCHROMIUM(
     DisjointValueSync* sync) {
   NOTIMPLEMENTED();
   return error::kNoError;
 }
 
 error::Error GLES2DecoderPassthroughImpl::DoInsertEventMarkerEXT(
     GLsizei length,
     const char* marker) {
-  NOTIMPLEMENTED();
+  if (!feature_info_->feature_flags().ext_debug_marker) {
+    return error::kUnknownCommand;
+  }
+
+  glInsertEventMarkerEXT(length, marker);
   return error::kNoError;
 }
 
 error::Error GLES2DecoderPassthroughImpl::DoPushGroupMarkerEXT(
     GLsizei length,
     const char* marker) {
-  NOTIMPLEMENTED();
+  if (!feature_info_->feature_flags().ext_debug_marker) {
+    return error::kUnknownCommand;
+  }
+
+  glPushGroupMarkerEXT(length, marker);
   return error::kNoError;
 }
 
 error::Error GLES2DecoderPassthroughImpl::DoPopGroupMarkerEXT() {
-  NOTIMPLEMENTED();
+  if (!feature_info_->feature_flags().ext_debug_marker) {
+    return error::kUnknownCommand;
+  }
+
+  glPopGroupMarkerEXT();
   return error::kNoError;
 }
 
 error::Error GLES2DecoderPassthroughImpl::DoGenVertexArraysOES(
     GLsizei n,
     volatile GLuint* arrays) {
   return GenHelper(
       n, arrays, &vertex_array_id_map_,
       [](GLsizei n, GLuint* arrays) { glGenVertexArraysOES(n, arrays); });
 }
@@ skipping 980 matching lines @@
     GLint x,
     GLint y,
     GLint width,
     GLint height) {
   NOTIMPLEMENTED();
   return error::kNoError;
 }
 
 }  // namespace gles2
 }  // namespace gpu