Google's official blog for Chrome and Chromebook announcements, covering browser releases, security features, and Android apps on Chromebooks.
HN commenters cite it as a source for security history: PDF sandboxing, Chromebook hardware security, and download checks, plus a Chrome April Fools joke.
Information is scarce on this (a little bit of security through obscurity).
Here is theirs blog post introducing the feature in 2012:
https://chrome.googleblog.com/2012/02/faster-browsing-safer-downloading.html
> Chrome also does checks on executable files (like ".exe" and ".msi" files). If the executable doesn't match a whitelist, Chrome checks with Google for more information, such as whether the website you're accessing hosts a high number of malicious downloads.
At the time I looked at the implementation in the Chrome source code, but I remember that it took me a while to locate it.
Flash is not entirely dead yet, so support can't be completely dropped. However, both Chrome [1] and Firefox [2] have announced long-term schedules for removing support for Flash, bit by bit.
As for PDF, the PDF viewers shipped in browsers seem to be much more hardened against attack than the stand alone ones people use, so as a practical matter, including a PDF viewer helps keep users safe.
[1] https://chrome.googleblog.com/2016/08/flash-and-chrome.html
[2] https://blog.mozilla.org/futurereleases/2016/07/20/reducing-adobe-flash-usage-in-firefox/
https://chrome.googleblog.com/2016/08/flash-and-chrome.html?google_comment_id=z124fncznsmhxbizv04cjz1rfxb3x1lav2w also echoes what you say:
I don't know what you guys changed under the hood, but I'm
experiencing the exact opposite of your first paragraph claims:
most videos don't work, and it's draining my macbook's battery
at an unprecedented rate. I can live with my flash videos not
working, but the reduced battery life is making chrome
unusable.
PDF parsing and rendering has been sandboxed for over a decade: https://chrome.googleblog.com/2010/11/pdf-goodness-in-chrome.html
The idea of depending on your government to protect you from exploits is insane. Anyone in the world can upload a shady PDF to a website hosted in any country and suffer zero consequences.
The most important advice you need to hear: your Flash tool is never going to get the adoption it might deserve because it's in Flash. Your potential user base is shrinking, not growing, and it is only going to shrink faster.
https://chrome.googleblog.com/2016/08/flash-and-chrome.html
This happened back in March of this year (2016)[0] They changed the name of the app in the various app stores a while back as well.
[0] - https://chrome.googleblog.com/2016/03/introducing-vizio-p-series-display-with.html