 Joe Medley [GitHub](https://github.com/jpmedley)
In nearly every version of Chrome, we see a significant number of updates and
improvements to the product, its performance, and also capabilities of the Web
Platform. This article describes the changes in Chrome 52, which is in beta as
of June 9. This list is subject to change at any time.
## Deprecate MediaStream ended event and attribute and onended attribute
**TL;DR:** The `ended` event and attribute and the `onended` event handler are being deprecated because they have been removed from the [Media Capture and Streams spec](https://www.w3.org/TR/mediacapture-streams/).
[Intent to Remove](https://groups.google.com/a/chromium.org/d/topic/blink-dev/EHy8zm0eVy0/discussion) \|
[Chromestatus Tracker](https://www.chromestatus.com/feature/5730404371791872) \|
[Chromium Bug](https://code.google.com/p/chromium/issues/detail?id=608795)
Neither the `ended` event, nor the `onended` event handler have been part of the WebRTC spec for about three years. Developers wanting to watch events should use [`MediaStreamTracks`](https://developer.mozilla.org/docs/Web/API/MediaStreamTrack) instead of `MediaStreams`.
Removal is anticipated in Chrome 53.
## Block pop-ups from cross-origin iframes during touch events except during a tap gesture
**TL;DR:** Chrome will begin disallowing pop-ups and other sensitive operations on touch events that don't correspond to a tap from inside of cross-origin iframes.
[Intent to Remove](https://groups.google.com/a/chromium.org/d/topic/blink-dev/piK75azdN5o/discussion) \|
[Chromestatus Tracker](https://www.chromestatus.com/feature/5649871251963904) \|
[Chromium Bug](https://code.google.com/p/chromium/issues/detail?id=582140)
By their very nature, touch events can be ambiguous when compared to their corresponding mouse events. For example, if a user slides a finger across the screen, is said user sliding a toggle switch or scrolling the view? Some third-party content in iframes have taken advantage of this ambiguity to intentionally disable scrolling on the containing page.
To combat this, pop-ups and other sensitive operations will be disallowed on touch events from cross-origin iframes. The touchend event will continue to behave as before.
## Deprecate overload of postMessage()
**TL;DR:** An unneeded and little-used variant of the `postMessage()` interface is being deprecated, specifically `postMessage(message, transferables, targetOrigin)`.
[Intent to Remove](https://groups.google.com/a/chromium.org/d/topic/blink-dev/h4ooaB_Y9JE/discussion) \|
[Chromestatus Tracker](https://www.chromestatus.com/feature/5719033043222528) \|
[Chromium Bug](https://code.google.com/p/chromium/issues/detail?id=425896)
The `postMessage()` method is a way to securely communicate between the scripts of pages on different origins. WebKit/Blink supports three versions:
- `postMessage(message, targetOrigin)`
- `postMessage(message, targetOrigin, transferables)`
- `postMessage(message, transferables, targetOrigin)`
The last item in this list was an accident from the history of the spec's evolution and implementation. Because it [is rarely used](https://www.chromestatus.com/metrics/feature/timeline/popularity/575), it will be deprecated and later removed. This applies to both `window.postMessage()` and `worker.postMessage()`.
Removal is anticipated in Chrome 54.
## Remove support for X-Frame-Options in tags
**TL;DR:** To both comply with the spec and increase consistency with other browsers, support for `X-Frame-Options` inside a `` tag is being removed.
[Intent to Remove](https://groups.google.com/a/chromium.org/d/topic/blink-dev/R1gkjKZI0J8/discussion) \|
[Chromium Bug](https://bugs.chromium.org/p/chromium/issues/detail?id=603002)
The `X-Frame-Options` HTTP response header indicates whether a browser can render a page in an``, `