GitLab

Use INPUT_EVENT_GPU_SWAP_BUFFER_COMPONENT instead of
INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT as the
final component to calculate input latency.

This will more accurately reflect latency regressions in the
code we have direct control of in Chrome.

Also make PassThroughImageTransportSurface::PostSubBuffer
add a INPUT_EVENT_GPU_SWAP_BUFFER_COMPONENT, which it
was missing before.

Followup patches will snap
INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT
to the next vsync to reflect the real display time.

The real display time can then be used for better
smoothness metrics and also to track latency regressions
at the OS/driver level for Ozone and potentially other
platforms where we can extract swap info.

BUG=360844

Review URL: https://codereview.chromium.org/918883002

Cr-Commit-Position: refs/heads/master@{#318812}