Hook ANGLE_request_extension up to the passthrough cmd decoder.

ui/gl/gl_mock_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 900 matching lines @@
                   GLsizei samples,
                   GLenum internalformat,
                   GLsizei width,
                   GLsizei height));
 MOCK_METHOD5(RenderbufferStorageMultisampleIMG,
              void(GLenum target,
                   GLsizei samples,
                   GLenum internalformat,
                   GLsizei width,
                   GLsizei height));
+MOCK_METHOD1(RequestExtensionANGLE, void(const char* name));
 MOCK_METHOD0(ResumeTransformFeedback, void());
 MOCK_METHOD2(SampleCoverage, void(GLclampf value, GLboolean invert));
 MOCK_METHOD3(SamplerParameterf,
              void(GLuint sampler, GLenum pname, GLfloat param));
 MOCK_METHOD3(SamplerParameterfv,
              void(GLuint sampler, GLenum pname, const GLfloat* params));
 MOCK_METHOD4(
     SamplerParameterfvRobustANGLE,
     void(GLuint sampler, GLenum pname, GLsizei bufSize, const GLfloat* param));
 MOCK_METHOD3(SamplerParameteri,
@@ skipping 278 matching lines @@
                   const void* ptr));
 MOCK_METHOD6(VertexAttribPointer,
              void(GLuint indx,
                   GLint size,
                   GLenum type,
                   GLboolean normalized,
                   GLsizei stride,
                   const void* ptr));
 MOCK_METHOD4(Viewport, void(GLint x, GLint y, GLsizei width, GLsizei height));
 MOCK_METHOD3(WaitSync, GLenum(GLsync sync, GLbitfield flags, GLuint64 timeout));