Switched from my 2011 Macbook Pro (where this bug was filed) to a 2014 Macbook Air.  Seems to not happen on the Air, with Chrome 56.0.2924.87 (64-bit) and the same MacOS version.

This could be related to number of layers. Turning on high-DPI mode on my macbook air (stable, 56.0.2924.87) and turning on layer overlays shows a vast number of layers for such a simple page.

Additionally, it looks like at least some of the layers are repainting even when I am not *doing* anything. 

Random hacking at CSS:

  * Removing overflow: auto; on md-content removes a good number of layers but not all.
  * Both the drop-down arrows on select boxes and the drop down arrows on the areas are all translated and transformed, so we promote them.
  * There are additional bezier transitions on many items, though I've been unable to get them to affect the number of layers yet.

With regards to the original memory issue, I am so far unable to reproduce quite such a severe increase using a Macbook Air with devtools-faking-high-DPI and the below Chrome versions.
 
Steps taken:

1. Opened Activity Monitor, checked system memory
2. Opened 4 tabs from the application, turn on devtools high DPI mode for each.
3. Scroll all 4 tabs for a while (few minutes)
4. Check memory (below).
5. Close tabs.

Chrome 56.0.2924.87 (64-bit):

System memory started at 4.64GB. At step 3, system memory was 6.16GB, a 1.52GB increase. Compressed memory did not change, nor any of the other metrics I could see. No specific Chrome process was high; top is a 'Google Chrome Helper' with 450MB, next is the browser process with 227MB.

After closing the tabs, memory used dropped to 4.99GB.


Chrome 59.0.3037.0 (64-bit):

System memory started at 3.87GB. At step 3, system memory was 5.34GB, a 1.47GB increase. Compressed memory did not change, nor any of the other metrics I could see. No specific Chrome process was high; top 3 were 'Google Chrome Helper's with ~450MB.

After closing the tabs, memory used dropped to 3.61GB.




I will try to find a Macbook pro to attempt reproduction on.

Note that this is a 2011 Macbook Pro, so it has a low-dpi screen, not a high-dpi one.  The bug I linked to at the top said something about it happening more often if memory was low at startup (this MBP has only 4 GB of RAM, so memory is always "low" by modern standards).  Since I've had this machine for 6 years now, I may have weird stuff in my chrome flags or something.  If there's an easy way to capture those, tell me the incantation and I can post it here.

Oh sorry, I had missed that it was an older Macbook Pro. In that case ignore everything I said in #4, #5, and #9! (I mean, the page still has a lot of layers on high DPI. But it's irrelevant to this bug.)

Is your Macbook Pro 2011 model 32 or 64 bit? (Should show up in the Chrome version at chrome://version afaik).

Just checked, the complete version string is:
  57.0.2987.88 (Official Build) beta (64-bit)
I'm surprised the auto-filled version field in the bug filing form leaves out the (64-bit) part.

Thank you for providing more feedback. Adding requester "schenney@chromium.org" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

I doubt this is Blink compositing.

(There hasn't been a 32 bit Mac Chrome release since early 2014, so it's omitted on Mac. Not that this helps with anything here.)

smcgruer: Are you planning on looking into this further?

Sorry; I had intended to try and reproduce on my Macbook Air on non-composited mode, but was not planning on investigating further after that. Since the problem occurred on low-DPI it isn't compositing related.

This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

Sorry for the inconvenience if the bug really should have been left as Available.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

I don't think this is reproducible or actionable any more. If it's happening on current Chrome releases on recent hardware and macOS releases please file a new bug.