Hook ANGLE_request_extension up to the passthrough cmd decoder.

ui/gl/gl_bindings_api_autogen_gl.h

 // Copyright 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.
 //
 // This file is auto-generated from
 // ui/gl/generate_bindings.py
 // It's formatted by clang-format using chromium coding style:
 //    clang-format -i -style=chromium filename
 // DO NOT EDIT!
 
@@ skipping 867 matching lines @@
 void glRenderbufferStorageMultisampleEXTFn(GLenum target,
                                            GLsizei samples,
                                            GLenum internalformat,
                                            GLsizei width,
                                            GLsizei height) override;
 void glRenderbufferStorageMultisampleIMGFn(GLenum target,
                                            GLsizei samples,
                                            GLenum internalformat,
                                            GLsizei width,
                                            GLsizei height) override;
+void glRequestExtensionANGLEFn(const char* name) override;
 void glResumeTransformFeedbackFn(void) override;
 void glSampleCoverageFn(GLclampf value, GLboolean invert) override;
 void glSamplerParameterfFn(GLuint sampler,
                            GLenum pname,
                            GLfloat param) override;
 void glSamplerParameterfvFn(GLuint sampler,
                             GLenum pname,
                             const GLfloat* params) override;
 void glSamplerParameterfvRobustANGLEFn(GLuint sampler,
                                        GLenum pname,
@@ skipping 315 matching lines @@
                               GLsizei stride,
                               const void* ptr) override;
 void glVertexAttribPointerFn(GLuint indx,
                              GLint size,
                              GLenum type,
                              GLboolean normalized,
                              GLsizei stride,
                              const void* ptr) override;
 void glViewportFn(GLint x, GLint y, GLsizei width, GLsizei height) override;
 GLenum glWaitSyncFn(GLsync sync, GLbitfield flags, GLuint64 timeout) override;