More SaveFlags removal twiddling.

More SaveFlags removal twiddling.

This is a follow up to https://codereview.chromium.org/338913002/. More
tweaks to allow migrating clients to the new API.

1) switch the shim call direction willSave(SaveFlags) -> willSave()
   (internal users are still using the former, so external overriders of
    the latter will not be notified otherwise - doh)
2) ensure willSave() stays visible in SkProxyCanvas (Chromium's
   TimingCanvas attempts to call it explicitly).

BUG=skia:2297
R=reed@google.com

Committed: https://skia.googlesource.com/skia/+/6ca763f362f25500ffeee0cc0b5dd2b58e9f2a79

[reed1, 2014-06-17 20:25:05]

still fretting over shadow warnings, but lgtm

[f(malita), 2014-06-17 20:35:49]

On 2014/06/17 20:25:05, reed1 wrote:
> still fretting over shadow warnings

I think that's what bit me with TimingCanvas: its superclass SkProxyCanvas only
overrides one version of willSave, and hides the other -- so TimingCanvas can no
longer call the obscured version. Fortunately this seems to be the only tricky
instance, and that "using" clause takes care of it for now.

[f(malita), 2014-06-17 20:36:13]

The CQ bit was checked by fmalita@chromium.org

[commit-bot: I haz the power, 2014-06-17 20:37:12]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/fmalita@chromium.org/334393008/20001

[commit-bot: I haz the power, 2014-06-17 20:52:21]

Change committed as 6ca763f362f25500ffeee0cc0b5dd2b58e9f2a79