Move flush id from WebGraphicsContext3DImpl to GLES2Implementation.

gpu/command_buffer/client/gles2_interface_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 763 matching lines @@
                                      GLuint background_color,
                                      GLuint edge_aa_mask,
                                      const GLfloat* bounds_rect,
                                      GLboolean is_clipped,
                                      const GLfloat* clip_rect,
                                      GLint sorting_context_id,
                                      const GLfloat* transform) = 0;
 virtual void CommitOverlayPlanesCHROMIUM() = 0;
 virtual void SwapInterval(GLint interval) = 0;
 virtual void FlushDriverCachesCHROMIUM() = 0;
+virtual GLuint GetLastFlushIdCHROMIUM() = 0;
 virtual void MatrixLoadfCHROMIUM(GLenum matrixMode, const GLfloat* m) = 0;
 virtual void MatrixLoadIdentityCHROMIUM(GLenum matrixMode) = 0;
 virtual GLuint GenPathsCHROMIUM(GLsizei range) = 0;
 virtual void DeletePathsCHROMIUM(GLuint path, GLsizei range) = 0;
 virtual GLboolean IsPathCHROMIUM(GLuint path) = 0;
 virtual void PathCommandsCHROMIUM(GLuint path,
                                   GLsizei numCommands,
                                   const GLubyte* commands,
                                   GLsizei numCoords,
                                   GLenum coordType,
@@ skipping 90 matching lines @@
                                             const char* name) = 0;
 virtual void BindFragDataLocationEXT(GLuint program,
                                      GLuint colorNumber,
                                      const char* name) = 0;
 virtual GLint GetFragDataIndexEXT(GLuint program, const char* name) = 0;
 virtual void UniformMatrix4fvStreamTextureMatrixCHROMIUM(
     GLint location,
     GLboolean transpose,
     const GLfloat* default_value) = 0;
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_INTERFACE_AUTOGEN_H_