I've been running Chrome with memory profiling enabled. I started with a gmail tab that I used for ~2 weeks. Then I forced a GC, navigated to about:blank, and then forced another GC. The renderer that was hosting the about:blank frame still has ~7 thousand objects created in extensions::MessagingBindings::OpenChannelToExtension that have not been destroyed. This seems likely to be a leak. These stats come from a renderer that is only hosting about:blank.

Raw & processed data: https://bugs.chromium.org/p/chromium/issues/detail?id=733323#c2
Methodology: https://docs.google.com/document/d/1fN5balfyrd7sRpd6DRaUI1TwoOwYjLyRSd7mwZT5US8/edit#

Each screenshot shows:
  1) # of objects created [that have not been destroyed]
  2) The stack trace of the code that created the object.
 

Deleted: Screen Shot 2017-06-15 at 11.09.14 AM.png 142 KB

	Screen Shot 2017-06-15 at 11.09.14 AM.png 142 KB View Download