If you frequently use your phone or tablet to browse the web, you've probably noticed how some websites randomly redirect you to a fake virus warning or other similar page. This is due to malicious ads breaking out of their frame, and forcing a redirect of the parent page to wherever they want. These harmful ads have infiltrated virtually every ad network, including Google AdSense/AdX.
Google's solution to this problem is a blocker for redirecting ads, which was announced in November of last year (this is separate from the general ad blocker that will arrive later this month). If an ad tried to hijack the parent page, Chrome would block it and tell the user what page it was trying to get to. However, there has been a great deal of confusion over when the feature will actually be turned on for everyone.
The blocker was originally supposed to arrive in Chrome 64, but it was still turned off by default. To make things more confusing, Google even listed the blocker in the official changelog. Thankfully, the feature's bug tracking page reveals what is actually going on.
The feature was turned off in Chrome 64 due to the info bar (seen in the screenshot above) not being implemented on all platforms. The blocker was disabled at the last minute, only a few days before Chrome 64 was released. That explains why the changelog was inaccurate.
Developers were aiming to ship the blocker in Chrome 65, which will be released this month, but it appears the feature has been delayed yet again. Unless it is delayed further, the blocker for redirecting ads will be included in Chrome 66, which is expected to come out in late April.
If you want to manually turn on the feature, and deal with whatever lingering bugs it currently has, it's pretty simple. Just copy chrome://flags/#enable-framebusting-needs-sameorigin-or-usergesture and paste it in the address bar (you can't tap on that link directly). Then tap the highlighted dropdown menu, change it to 'Enabled,' and restart the browser when asked.