Add glWaitSync to GPU command buffer.

gpu/command_buffer/client/gles2_implementation_autogen.h

 // 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.
 
 // This file is auto-generated from
 // gpu/command_buffer/build_gles2_cmd_buffer.py
 // It's formatted by clang-format using chromium coding style:
 //    clang-format -i -style=chromium filename
 // DO NOT EDIT!
 
@@ skipping 686 matching lines @@
 
 void VertexAttribPointer(GLuint indx,
                          GLint size,
                          GLenum type,
                          GLboolean normalized,
                          GLsizei stride,
                          const void* ptr) override;
 
 void Viewport(GLint x, GLint y, GLsizei width, GLsizei height) override;
 
+void WaitSync(GLsync sync, GLbitfield flags, GLuint64 timeout) override;
+
 void BlitFramebufferCHROMIUM(GLint srcX0,
                              GLint srcY0,
                              GLint srcX1,
                              GLint srcY1,
                              GLint dstX0,
                              GLint dstY0,
                              GLint dstX1,
                              GLint dstY1,
                              GLbitfield mask,
                              GLenum filter) override;
@@ skipping 259 matching lines @@
 
 void SwapInterval(GLint interval) override;
 
 void MatrixLoadfCHROMIUM(GLenum matrixMode, const GLfloat* m) override;
 
 void MatrixLoadIdentityCHROMIUM(GLenum matrixMode) override;
 
 void BlendBarrierKHR() override;
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_AUTOGEN_H_