Add glClientWaitSync to GPU command buffer.

gpu/command_buffer/client/gles2_interface_stub_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 51 matching lines @@
                    const GLint* value) override;
 void ClearBufferuiv(GLenum buffer,
                     GLint drawbuffers,
                     const GLuint* value) override;
 void ClearColor(GLclampf red,
                 GLclampf green,
                 GLclampf blue,
                 GLclampf alpha) override;
 void ClearDepthf(GLclampf depth) override;
 void ClearStencil(GLint s) override;
+GLenum ClientWaitSync(GLsync sync, GLbitfield flags, GLuint64 timeout) override;
 void ColorMask(GLboolean red,
                GLboolean green,
                GLboolean blue,
                GLboolean alpha) override;
 void CompileShader(GLuint shader) override;
 void CompressedTexImage2D(GLenum target,
                           GLint level,
                           GLenum internalformat,
                           GLsizei width,
                           GLsizei height,
@@ skipping 610 matching lines @@
                                   GLint bounds_height,
                                   GLfloat uv_x,
                                   GLfloat uv_y,
                                   GLfloat uv_width,
                                   GLfloat uv_height) override;
 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_INTERFACE_STUB_AUTOGEN_H_