Loosen FirstMeaningfulPaint UMA network-idle heuristics
Currently, FirstMeaningfulPaint (FMP) UMA is logged when page's network
activity is "0-quiet" (no network requests) for 0.5 seconds. But about
23% of page loads are aborted before reaching that condition.
To improve the coverage of FMP UMA, this patch changes the network idle
heuristic to "2-quiet" (no more than 2 network requests) for 3 seconds
window.
To verify this change doesn't make FMP reported too soon,
FirstMeaningfulPaintDetector continues to observe layouts until network
0-quiet, and report whether the last FMP candidate was after network
2-quiet or not.
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Review-Url: https://codereview.chromium.org/2711893002
Cr-Commit-Position: refs/heads/master@{#457017}
8 files changed
