Add support for EXT_image_flush_external extension

ui/gl/gl_bindings_api_autogen_egl.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
 // 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 73 matching lines @@
     const char* procname) override;
 EGLBoolean eglGetSyncAttribKHRFn(EGLDisplay dpy,
                                  EGLSyncKHR sync,
                                  EGLint attribute,
                                  EGLint* value) override;
 EGLBoolean eglGetSyncValuesCHROMIUMFn(EGLDisplay dpy,
                                       EGLSurface surface,
                                       EGLuint64CHROMIUM* ust,
                                       EGLuint64CHROMIUM* msc,
                                       EGLuint64CHROMIUM* sbc) override;
+EGLBoolean eglImageFlushExternalEXTFn(EGLDisplay dpy,
+                                      EGLImageKHR image,
+                                      const EGLAttrib* attrib_list) override;
 EGLBoolean eglInitializeFn(EGLDisplay dpy,
                            EGLint* major,
                            EGLint* minor) override;
 EGLBoolean eglMakeCurrentFn(EGLDisplay dpy,
                             EGLSurface draw,
                             EGLSurface read,
                             EGLContext ctx) override;
 EGLBoolean eglPostSubBufferNVFn(EGLDisplay dpy,
                                 EGLSurface surface,
                                 EGLint x,
@@ skipping 50 matching lines @@
                               EGLSurface surface,
                               EGLint attribute,
                               EGLint value) override;
 EGLBoolean eglSwapBuffersFn(EGLDisplay dpy, EGLSurface surface) override;
 EGLBoolean eglSwapIntervalFn(EGLDisplay dpy, EGLint interval) override;
 EGLBoolean eglTerminateFn(EGLDisplay dpy) override;
 EGLBoolean eglWaitClientFn(void) override;
 EGLBoolean eglWaitGLFn(void) override;
 EGLBoolean eglWaitNativeFn(EGLint engine) override;
 EGLint eglWaitSyncKHRFn(EGLDisplay dpy, EGLSyncKHR sync, EGLint flags) override;