cc: Remove 3 virtual function calls per display item during record.

cc: Remove 3 virtual function calls per display item during record.

During record we compute the "is suitable for gpu raster", the "approx
operation count" and the "memory usage" for each display item. It does
this by calling a virtual function on each display item for each of
these.

Instead, store them as fields in display item, have them filled in by
the subclass when they set up their data, and just read them directly
while walking the display items in the list and summing them up.

This provides a change for a single tab spinner in the UI compositor
from 0.201342 ms to 0.181608 which is a 10% improvement in record time
(time spent in LayerTreeHost::UpdateLayers).

R=enne
BUG=466426

Review URL: https://codereview.chromium.org/1135923003

Cr-Commit-Position: refs/heads/master@{#329199}