Revert of Deparameterize SkVarAlloc.

Revert of Deparameterize SkVarAlloc. (patchset #6 id:100001 of https://codereview.chromium.org/721313002/)

Reason for revert:
Unit test failures on 32-bit machines.

test Record_Alignment: ../../tests/RecordTest.cpp:100	is_aligned(record.alloc<uint64_t>())

Original issue's description:
> Deparameterize SkVarAlloc.
> 
> SkRecord performance is not sensitive to these values, so we can cut some
> storage.  This rearranges the space-remaining logic to use a count of bytes
> left rather than a pointer to the end, cutting memory usage a little more.
> 
> An SkVarAlloc used to weigh 20 or 32 bytes which now becomes 16 or 24.
> 
> I think if I think about it a bit more I can trim off that Block* too,
> getting us to 12 or 16 bytes.
> 
> Because we now just always grow by doubling, this CL switches from storing
> fSmallest to its log base 2.  This has the nice effect of never having to worry
> about it overflowing, and means we can probably squeeze it down into a byte
> if we want, even 6 bits.
> 
> BUG=skia:
> 
> Committed: https://skia.googlesource.com/skia/+/bc415389855888af5a1282ca4b6bee30afa3d69d

TBR=reed@google.com,mtklein@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Committed: https://skia.googlesource.com/skia/+/dfd5f6edf83ff6b42bf38f03b9633c65d80eb6cb

[mtklein, 2014-11-13 19:22:31]

Created Revert of Deparameterize SkVarAlloc.

[commit-bot: I haz the power, 2014-11-13 19:23:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/718203006/1

[commit-bot: I haz the power, 2014-11-13 19:23:40]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/dfd5f6edf83ff6b42bf38f03b9633c65d80eb6cb