[WebBlobRegistry] Use char* than WebThreadSafeData

[WebBlobRegistry] Use char* than WebThreadSafeData

We don't need to wrap the data with WebThreadSafeData here. Just use a
pair of const char* and size_t.

This is Chromium side CL

Blink side CL: https://codereview.chromium.org/611923002/

R=yhirano,jam
BUG=417093
Committed: https://crrev.com/703e7a89e3f4db15967e3710ef7353b484dd0a5b
Cr-Commit-Position: refs/heads/master@{#300064}

[yhirano, 2014-09-29 08:54:22]

yhirano@chromium.org changed reviewers:
+ yhirano@chromium.org

[yhirano, 2014-09-29 08:54:22]

lgtm

[tyoshino (SeeGerritForStatus), 2014-09-30 02:14:48]

tyoshino@chromium.org changed reviewers:
+ jam@chromium.org

[tyoshino (SeeGerritForStatus), 2014-10-02 03:23:13]

jam, please take a look.

[jam, 2014-10-06 23:24:58]

lgtm

sorry for the delay

[tyoshino (SeeGerritForStatus), 2014-10-16 09:13:43]

The CQ bit was checked by tyoshino@chromium.org

[commit-bot: I haz the power, 2014-10-16 09:14:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/610333002/60001

[commit-bot: I haz the power, 2014-10-16 10:19:43]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-10-16 10:19:44]

Try jobs failed on following builders:
  win_gpu_triggered_tests on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/win_gpu_triggered...)

[tyoshino (SeeGerritForStatus), 2014-10-17 04:49:51]

The CQ bit was checked by tyoshino@chromium.org

[commit-bot: I haz the power, 2014-10-17 04:50:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/610333002/60001

[commit-bot: I haz the power, 2014-10-17 04:51:25]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2014-10-17 04:52:26]

Patchset 4 (id:??) landed as
https://crrev.com/703e7a89e3f4db15967e3710ef7353b484dd0a5b
Cr-Commit-Position: refs/heads/master@{#300064}