I have faced the same issue on Ubuntu 16.04 with recent Chrome Dev releases. I can't reproduce this now with steps given here or how I originally encountered it 
which is pretty similar (by clicking on link that lead to a download). 

Unable to reproduce this issue on Windows 10 with chrome dev #58.0.3004.3, observed  download was completed successfully and not seen any spike in CPU usage and browser crash.

Attaching a screen-cast for reference 

paul.betts@ could you please re-try the same scenario with clean profile with no apps/extensions and let us know your observations.

Deleted: Issue 692186.mp4 801 KB

	Issue 692186.mp4 801 KB View Download

I experienced this issue as well.

Google Chrome	58.0.3004.3 (Official Build) dev (32-bit)
Revision	748a9b8eaae6a2a2d9870544166f8adf670b7a80-refs/branch-heads/3004@{#4}
OS	Windows

I'm not 100% sure, but I feel it only happens when download finishes before the user closed the save dialog, or when the URL is already in local cache. I suspect it is some form of IPC race condition.

1. Tried the same version with a clean profile, still crash.
2. Disabled all extensions and flash on the clean profile, still crash.
3. Tried the closest chromium snapshot: https://www.googleapis.com/download/storage/v1/b/chromium-browser-snapshots/o/Win%2F448183%2Fchrome-win32.zip?generation=1486290657374161&alt=media , doesn't crash.

This is my personal computer so I don't have access to the official build archive. Trying to find a way to bisect. :/

I tried the same version 58.0.3004.3/chrome-win-pgo from the official archive, but it doesn't crash either, so it is very likely one of the variation.

The most related experiment we have right now is DownloadAttribution. I tried to run chrome with "chrome --disable-features=DownloadAttribution" twice, both times didn't crash. Then I also tried "chrome --enable-features=DownloadAttribution" twice, both times crashed. It felt the repro wasn't very reliable so it could still be a flake, but at this moment it is the most probable suspect.

Assigning to jialiul@ for further investigation.

paul.betts@: Could you describe your repro in greater detail? In my repro the browser doesn't hang immediately after clicking the link. It only hangs after clicking through save dialog, and doesn't hang if I hit cancel. Did you use a default save location? Also please paste your chrome://version/ , does it contain cf558fa6-48a16532 ? Any clue will be greatly appreciated, and thanks for reporting!

It is probably related to https://bugs.chromium.org/p/chromium/issues/detail?id=687041, which has already been fixed in 58.0.3008.*.

Issue 692326 has been merged into this issue.

Tested on head and latest canary with DownloadAttribution experiment enabled, no longer crashing.
Mark as fixed.