Remove GraphicsContext's deferred save mechanism.

Remove GraphicsContext's deferred save mechanism.

The new Skia recording backend is not as sensitive to the number of draw
ops as the old one -> we don't have to bend over backwards to suppress
unneeded saves at the GC level.

While this results in a slight increase in the number of recorded ops,
the unnecessary saves and restores are optimized out by the bounding box
hierarchy - so there is no playback/rasterization time penalty (Skia
also has an explicit save/restore optimizer which can be used for this
purpose if we ever decide to drop the BBH).

Local perf measurements show no rasterization impact and a minor (<1%)
improvement for record time.

R=schenney@chromium.org,senorblanco@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=183750

[Stephen Chennney, 2014-10-15 13:46:43]

Glad to see it go. LGTM

[Stephen White, 2014-10-15 13:56:34]

LGTM too.

[f(malita), 2014-10-15 13:57:29]

The CQ bit was checked by fmalita@chromium.org

[commit-bot: I haz the power, 2014-10-15 13:58:22]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/653153004/60001

[commit-bot: I haz the power, 2014-10-15 14:01:32]

Committed patchset #4 (id:60001) as 183750

[mtklein, 2014-10-15 14:02:33]

mtklein@google.com changed reviewers:
+ mtklein@google.com

[mtklein, 2014-10-15 14:02:34]

Neat!