Reland Initial ServiceWorker Cache API polyfill.

Reland Initial ServiceWorker Cache API polyfill.

Originally landed as r175749, this had to revert because of a memory
issue; the file arrays were not null terminated. Now using the
explicit length WTFString constructor.

R=jsbell@chromium.org,dcheng@chromium.org
TBR=jochen@chromium.org
BUG=374822
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=175808

[gavinp, 2014-06-09 11:55:30]

dcheng: FYI since you reverted.

jsbell, can you CQ this if you approve? I'm writing this sitting on an airplane
that's about to close its door. (see you in California this week)

[jsbell, 2014-06-09 17:33:54]

lgtm

[jsbell, 2014-06-09 17:33:57]

The CQ bit was checked by jsbell@chromium.org

[commit-bot: I haz the power, 2014-06-09 17:35:02]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/gavinp@chromium.org/325683003/40001

[commit-bot: I haz the power, 2014-06-09 17:43:28]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  blink_presubmit on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/blink_presubmit/builds/7305)

[commit-bot: I haz the power, 2014-06-09 17:45:37]

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

[commit-bot: I haz the power, 2014-06-09 17:45:38]

Try jobs failed on following builders:
  blink_presubmit on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/blink_presubmit/builds/7306)

[jsbell, 2014-06-09 17:46:16]

On 2014/06/09 17:45:38, I haz the power (commit-bot) wrote:
> Try jobs failed on following builders:
>   blink_presubmit on tryserver.blink
>
(http://build.chromium.org/p/tryserver.blink/builders/blink_presubmit/builds/7306)

Added a TBR for jochen for the modules.gyp change. Rechecking...

[jsbell, 2014-06-09 17:46:20]

The CQ bit was checked by jsbell@chromium.org

[commit-bot: I haz the power, 2014-06-09 17:47:38]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/gavinp@chromium.org/325683003/40001

[commit-bot: I haz the power, 2014-06-09 17:50:27]

Change committed as 175808