Scanner / Unicode decoding: use size_t instead of unsigned.

Scanner / Unicode decoding: use size_t instead of unsigned.

size_t is the correct data type for this purpose. Our APIs (in particular
ExternalSourceStream::GetMoreData) are already using it, and there were some
static_casts to convert between them.

This CL doesn't intend to fix all of V8, just the minimal sense-making part
around scanner character streams.

BUG=

Committed: https://crrev.com/0e3b5386aec539599c241bac09a25a8b5d2a4ef5
Cr-Commit-Position: refs/heads/master@{#26449}

[marja, 2015-02-04 13:51:24]

marja@chromium.org changed reviewers:
+ svenpanne@chromium.org

[marja, 2015-02-04 13:51:25]

svenpanne, ptal. This is an old-ish problem, this CL is trying to make the API
consistent with scanner character streams. The downside is that the border
between size_t and other random types V8 uses will always be somewhere until all
of it is fixed... so this is a stab at moving it forward.

[Sven Panne, 2015-02-05 07:52:10]

The CQ bit was checked by svenpanne@chromium.org

[Sven Panne, 2015-02-05 07:52:10]

lgtm

[commit-bot: I haz the power, 2015-02-05 07:52:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/864273005/80001

[commit-bot: I haz the power, 2015-02-05 07:54:33]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2015-02-05 07:54:46]

Patchset 5 (id:??) landed as
https://crrev.com/0e3b5386aec539599c241bac09a25a8b5d2a4ef5
Cr-Commit-Position: refs/heads/master@{#26449}