Make ServiceWorkerCacheStorage::CacheLoader::LoadCache synchronous

Make ServiceWorkerCacheStorage::CacheLoader::LoadCache synchronous

The CacheLoader has two functions for creating a cache:
1. LoadCache -- mkdir the cache directory and load the cache into memory
2. CreateCache  -- rm -rf the directory and then call LoadCache

This CL:

1. Makes LoadCache synchronous by moving the mkdir to CreateCache (in case of loading an existing cache the mkdir was unnecessary)
2. Deletes a bunch of async code
3. Renames LoadCache to CreateServiceWorkerCache

Related CLs:
1. https://crrev.com/542703002: Change ownership of the parameters to ServiceWorkerCache:: Put and Match.
2. https://crrev.com/545533002: Move ServiceWorkerCache backend creation to a lazy init function.
* 3. https://crrev.com/548533002: Make ServiceWorkerCacheStorage::CacheLoader::LoadCache synchronous
4. https://crrev.com/549493002: Expose ServiceWorkerCache objects to ServiceWorkerCacheStorageManager clients.

BUG=392621
Committed: https://crrev.com/43027f011bbc299acd7c4b67a9307ac9512e1df3
Cr-Commit-Position: refs/heads/master@{#294377}

[jkarlin, 2014-09-05 16:09:51]

jkarlin@chromium.org changed reviewers:
+ michaeln@chromium.org

[jkarlin, 2014-09-05 16:09:52]

Please take a look at everything, thanks!

[michaeln, 2014-09-09 03:27:44]

lgtm

https://codereview.chromium.org/548533002/diff/1/content/browser/service_work...
File content/browser/service_worker/service_worker_cache_storage.cc (right):

https://codereview.chromium.org/548533002/diff/1/content/browser/service_work...
content/browser/service_worker/service_worker_cache_storage.cc:61: // doesn't
exist a new one is created.
can you update the comment, looks like this can no longer return null, it's a
wrapper around a call to new ServiceWorkerCache(...)

[jkarlin, 2014-09-09 19:18:49]

https://codereview.chromium.org/548533002/diff/1/content/browser/service_work...
File content/browser/service_worker/service_worker_cache_storage.cc (right):

https://codereview.chromium.org/548533002/diff/1/content/browser/service_work...
content/browser/service_worker/service_worker_cache_storage.cc:61: // doesn't
exist a new one is created.
On 2014/09/09 03:27:44, michaeln wrote:
> can you update the comment, looks like this can no longer return null, it's a
> wrapper around a call to new ServiceWorkerCache(...)

Done.

[jkarlin, 2014-09-11 11:56:28]

The CQ bit was checked by jkarlin@chromium.org

[commit-bot: I haz the power, 2014-09-11 11:57:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/548533002/80001

[commit-bot: I haz the power, 2014-09-11 13:13:45]

Committed patchset #5 (id:80001) as 3b0e5301549d81d14344678be6f220ff0ffd8dc6

[commit-bot: I haz the power, 2014-09-11 13:17:07]

Patchset 5 (id:??) landed as
https://crrev.com/43027f011bbc299acd7c4b67a9307ac9512e1df3
Cr-Commit-Position: refs/heads/master@{#294377}