Files:
https://drive.google.com/a/google.com/file/d/0B6ho_7_ut5e1ZEViQmUxTjd1aEE/view?usp=sharing

Attaching potential leaks from the post-about:blank post-GC native heap dump.

Deleted: process_10717_malloc-leaks.json 164 KB

process_10717_malloc-leaks.json 164 KB View Download

Deleted: process_10717_partition_alloc-leaks.json 427 KB

process_10717_partition_alloc-leaks.json 427 KB View Download

Deleted: process_10721_blink_gc-objects.json 183 KB

process_10721_blink_gc-objects.json 183 KB View Download

+ keishi

Since we're now looking at allocations in a post-GC about:blank renderer, all of these giant allocations are Blink leaks, right?

Attaching blink-gc leaks. c#2 had blink_gc-objects.

Deleted: process_10717_blink_gc-leaks.json 264 KB

process_10717_blink_gc-leaks.json 264 KB View Download

Which tool should I use to look at the json files from c#2 and c#4?

Judging from the heapsnapshot files from c#1, post_blank_and_gc seems to be much smaller. But do you think there is a leak persisting post navigation to about:blank?

Any JSON viewer, like http://jsonviewer.stack.hu/.

Each leak consists of, # of objects alive, and trace of the stack that caused the object to be allocated.

Looking at partition_alloc leaks...
first potential leak: 48k objects created in blink::CSSSelectorList::AdoptSelectorVector

second potential leak: 34k objects created in blink::CSSSelectorList::AdoptSelectorVector

third potential leak: 20k objects created in blink::CSSSelectorList::AdoptSelectorVector

fourth potential leak: 20k objects created in blink::CSSSelectorList::AdoptSelectorVector

fifth potential leak: 16k strings created in blink::CSSSelectorParser::ConsumeClass.

and so on.

By looking to #c9, there is a probably repro for this leak:
  https://clusterfuzz.com/v2/testcase-detail/5515632539074560

Probably the same bug than:
  https://bugs.chromium.org/p/chromium/issues/detail?id=733714

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