IDL: Add [FlexibleArrayBufferView] and use for bufferSubData

Source/core/html/canvas/WebGLRenderingContextBase.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 472 matching lines @@
     void blendColor(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha);
     void blendEquation(GLenum mode);
     void blendEquationSeparate(GLenum modeRGB, GLenum modeAlpha);
     void blendFunc(GLenum sfactor, GLenum dfactor);
     void blendFuncSeparate(GLenum srcRGB, GLenum dstRGB, GLenum srcAlpha, GLenum dstAlpha);
     // FIXME: should be union type
     // https://www.khronos.org/bugzilla/show_bug.cgi?id=1172
     void bufferData(GLenum target, GLsizeiptr size, GLenum usage);
     void bufferData(GLenum target, ArrayBufferView data, GLenum usage);
     void bufferData(GLenum target, ArrayBuffer? data, GLenum usage);
-    void bufferSubData(GLenum target, GLintptr offset, ArrayBufferView data);
+    void bufferSubData(GLenum target, GLintptr offset, [FlexibleArrayBufferView] ArrayBufferView data);
     void bufferSubData(GLenum target, GLintptr offset, ArrayBuffer? data);
 
     GLenum checkFramebufferStatus(GLenum target);
     void clear(GLbitfield mask);
     void clearColor(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha);
     void clearDepth(GLclampf depth);
     void clearStencil(GLint s);
     void colorMask(GLboolean red, GLboolean green, GLboolean blue, GLboolean alpha);
     void compileShader(WebGLShader? shader);
 
@@ skipping 191 matching lines @@
     void vertexAttrib3fv(GLuint indx, Float32Array values);
     void vertexAttrib3fv(GLuint indx, sequence<GLfloat> values);
     void vertexAttrib4f(GLuint indx, GLfloat x, GLfloat y, GLfloat z, GLfloat w);
     void vertexAttrib4fv(GLuint indx, Float32Array values);
     void vertexAttrib4fv(GLuint indx, sequence<GLfloat> values);
     void vertexAttribPointer(GLuint indx, GLint size, GLenum type, GLboolean normalized,
                              GLsizei stride, GLintptr offset);
 
     void viewport(GLint x, GLint y, GLsizei width, GLsizei height);
 };