commit 30f282ecdc96f1da93b0558acbee6c95f0e5d92c
author Nicolás Peña Moreno <npm@chromium.org> Tue Jul 23 19:57:40 2019
committer Commit Bot <commit-bot@chromium.org> Tue Jul 23 19:57:40 2019
tree 3bcfb615e7af094b6885b43ab59fca436e113dc1
parent 310ef9226d1a99e0af091f35e56de68a500e28f9

[ElementTiming] Replace responseEnd with loadTime

This CL replaces responseEnd with loadTime in ElementTiming. Before,
responseEnd would be used and would be problematic for memory cached
images and for inline images (data scheme). We change it to loadTime,
the time at which LayoutObject::ImageNotifyFinished is called. This is
the same time as when LargestContentfulPaint computes loadTime. As they
are both under runtime flags and the hooks are not unified, for
simplicity we compute the timestamp again. This will not be too
expensive for ElementTiming, as the timestamp is gated on the existence
of the elementtiming attribute.

To store the loadTime, we change images_notified_ to be a HashMap which
now stores the timestamp corresponding to loadTime and whether the image
has painted (after being loaded).

Bug: 982046, 879270
Change-Id: I69da42c9250cc36c567df5da285ef1a9a357b554
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1710840
Commit-Queue: Nicolás Peña Moreno <npm@chromium.org>
Reviewed-by: Steve Kobes <skobes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#680117}