Update WebKit IDLs after chrome roll.

html/canvas/WebGLRenderingContext.idl

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 22 matching lines @@
 typedef long long      GLintptr;
 typedef long long      GLsizeiptr;
 typedef octet          GLubyte;        /* 'octet' should be an unsigned 8 bit type. */
 typedef unsigned short GLushort;
 typedef unsigned long  GLuint;
 typedef /*unrestricted*/ float GLfloat;
 typedef /*unrestricted*/ float GLclampf;
 
 [
     Conditional=WEBGL,
-    JSCustomMarkFunction,
     DoNotCheckConstants
 ] interface WebGLRenderingContext : CanvasRenderingContext {
 
     /* ClearBufferMask */
     const GLenum DEPTH_BUFFER_BIT               = 0x00000100;
     const GLenum STENCIL_BUFFER_BIT             = 0x00000400;
     const GLenum COLOR_BUFFER_BIT               = 0x00004000;
 
     /* BeginMode */
     const GLenum POINTS                         = 0x0000;
@@ skipping 607 matching lines @@
     [StrictTypeChecking, Custom] void vertexAttrib2fv(in GLuint indx, in Float32Array values);
     [StrictTypeChecking] void         vertexAttrib3f(in GLuint indx, in GLfloat x, in GLfloat y, in GLfloat z);
     [StrictTypeChecking, Custom] void vertexAttrib3fv(in GLuint indx, in Float32Array values);
     [StrictTypeChecking] void         vertexAttrib4f(in GLuint indx, in GLfloat x, in GLfloat y, in GLfloat z, in GLfloat w);
     [StrictTypeChecking, Custom] void vertexAttrib4fv(in GLuint indx, in Float32Array values);
     [StrictTypeChecking] void         vertexAttribPointer(in GLuint indx, in GLint size, in GLenum type, in GLboolean normalized, 
                                                           in GLsizei stride, in GLintptr offset) raises(DOMException);
 
     [StrictTypeChecking] void         viewport(in GLint x, in GLint y, in GLsizei width, in GLsizei height);
 };