Hide SaveFlags from the public SkCanvas API.

Hide SaveFlags from the public SkCanvas API.

After removing most internal and external (non-Android) users, this is
finally tractable - but not pretty by any stretch of imagination.

Android still needs to support the old API - hence the guard
(SK_SUPPORT_LEGACY_SAVEFLAGS).

R=reed@google.com,robertphillips@google.com,mtklein@google.com,scroggo@google.com

[f(malita), 2014-04-23 16:45:18]

I'm torn on this one: supporting both code paths could be too much of a burden
going forward.

Maybe we can simply mark the old API for deprecation and wait for clients to
transition: https://codereview.chromium.org/246023008/

[scroggo, 2014-04-23 17:52:21]

On 2014/04/23 16:45:18, Florin Malita wrote:
> I'm torn on this one: supporting both code paths could be too much of a burden
> going forward.
> 
> Maybe we can simply mark the old API for deprecation and wait for clients to
> transition: https://codereview.chromium.org/246023008/

Is there a plan for transitioning Android? skbug.com/2440 tracks part of the
problem:
providing another way to get the behavior from
SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG. We
also need to do something to support Canvas.java's save/saveLayer with flags API
(or
convince them to deprecate, which they seem to be hesitant to do - see
https://googleplex-android-review.git.corp.google.com/#/c/439622/).