This is a sub-issue of the larger fingerprint defense reorganization issue: #8787

Capability Probing Endpoints

WebGLRenderingContext.getFramebufferAttachmentParameter
WebGLRenderingContext.getActiveAttrib
WebGLRenderingContext.getActiveUniform
WebGLRenderingContext.getAttribLocation
WebGLRenderingContext.getBufferParameter
WebGLRenderingContext.getExtension
WebGLRenderingContext.getFrameBufferAttachmentParameter
WebGLRenderingContext.getProgramParameter
WebGLRenderingContext.getRenderBufferParameter
WebGLRenderingContext.getShaderParameter
WebGLRenderingContext.getShaderPrecisionFormat
WebGLRenderingContext.getTexParameter
WebGLRenderingContext.getUniformLocation
WebGLRenderingContext.getVertexAttribOffset
WebGLRenderingContext.readPixels

default protection: no changes
max protection: return corresponding bottom value (empty object, zero, etc, depending on the method's return value)