WebCrypto: [refactor] Use "unsigned" rather than "size_t" for buffer sizes.

WebCrypto: [refactor] Use "unsigned" rather than "size_t" for buffer sizes in the public API.

Justification:

I have noticed some instances where the Chromium-side implementation is directly passing this "size_t" as the buffer length to NSS.

NSS however expects buffer lengths as "unsigned int", and the C++ compiler implicitly converts the "size_t" to an "unsigned int". This conversion is dangerous, since theoretically it could result in truncation of the buffer length given to NSS. (Under LP64 datamodel for instance).

Chromium's compilation settings don't warn about such issues.

In practice this isn't a problem, and likely never will be, since in Blink ArrayBuffers are limited to lengths of 2^32-1.

It is therefore a good idea to pass a narrower datatype in the API to make this obvious. Embedder shouldn't have to worry about dealing with buffer sizes in the full range of size_t.

BUG=245025
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=157532

[abarth-chromium, 2013-09-09 18:39:52]

lgtm

[commit-bot: I haz the power, 2013-09-09 18:41:46]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/eroman@chromium.org/23537027/2001

[commit-bot: I haz the power, 2013-09-09 19:11:04]

Sorry for I got bad news for ya.
Compile failed with a clobber build on mac_layout.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac_layout...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[eroman, 2013-09-09 19:31:10]

(Added a deprecated version to keep chromium compiling)

[commit-bot: I haz the power, 2013-09-09 19:31:26]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/eroman@chromium.org/23537027/11001

[commit-bot: I haz the power, 2013-09-09 20:32:43]

Retried try job too often on win_blink_rel for step(s) webkit_lint,
webkit_python_tests, webkit_tests, webkit_unit_tests, weborigin_unittests,
wtf_unittests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_blink_...

[commit-bot: I haz the power, 2013-09-10 00:04:55]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/eroman@chromium.org/23537027/24001

[commit-bot: I haz the power, 2013-09-10 00:36:55]

Sorry for I got bad news for ya.
Compile failed with a clobber build on mac_layout.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac_layout...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2013-09-10 16:56:45]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/eroman@chromium.org/23537027/35001

[commit-bot: I haz the power, 2013-09-10 18:10:56]

Change committed as 157532