Revert "simplify SkTFitsIn, try 2"

This reverts commit 009f51e43fee199a579ecdd773e3aa35aaa3b8b8.

Reason for revert: unintentional header consequences in Chromium... will reland after fixing Chromium

Original change's description:
> simplify SkTFitsIn, try 2
> 
> Originally we wrote this in C++14 constexpr,
> but because this is used from public headers, we can't use
> C++14 yet.  Now a somewhat sillier looking C++11 version.
> 
> All the old tests still pass, and one new added.
> Updated the comments a bit for correctness and readability.
> 
> Change-Id: I99c01e1346c1a5a36278cc08f30538112e5259aa
> Reviewed-on: https://skia-review.googlesource.com/134425
> Commit-Queue: Mike Klein <mtklein@chromium.org>
> Commit-Queue: Ben Wagner <bungeman@google.com>
> Auto-Submit: Mike Klein <mtklein@chromium.org>
> Reviewed-by: Ben Wagner <bungeman@google.com>

TBR=mtklein@chromium.org,bungeman@google.com

Change-Id: Ic73f8800bd022ffea125b3b1bf138fe49c0db926
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/134621
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
2 files changed