The read-only WebGLRenderingContext.drawingBufferHeight property represents the actual height of the current drawing buffer. It should match the height attribute of the <canvas> element associated with this context, but might differ if the implementation is not able to provide the requested height.
The read-only WebGLRenderingContext.drawingBufferWidth property represents the actual width of the current drawing buffer. It should match the width attribute of the <canvas> element associated with this context, but might differ if the implementation is not able to provide the requested width.
The XMLHttpRequest.upload property returns an XMLHttpRequestUpload object, representing the upload process. It is an opaque object, but being an XMLHttpRequestEventTarget, event listeners can be set on it to track its process.
The CryptoKey.type read-only property that indicates the type of the key: if it is the key for a symmetric algorithm ("secret") or for an asymmetric algorithm ("public" or "private", depending of its purpose).
The Document.fullscreenEnabled read-only property returns a Boolean that reports whether or not full-screen mode is available. Full screen mode is available only for a page that has no windowed plug-ins in any of its documents, and if all <iframe> elements which contain the document have their allowfullscreen attribute set.