ServiceWorker: Decompose SWRegistration::SetVersionInternal for readability

ServiceWorker: Decompose SWRegistration::SetVersionInternal for readability

Originally SetVersionInternal() was quite simple function, but that has been
puzzuled as the codebase has evolved.

This CL decomposes the function for readability and simplifies lifetime
management for a version to be set, that is, passes a refcounted version
as an argument instead of making temporary protect object.

BUG=n/a
TEST=n/a

Committed: https://crrev.com/964b57ac5be1001f57dfb03262454324ef8b173a
Cr-Commit-Position: refs/heads/master@{#326753}

[nhiroki, 2015-04-24 04:03:40]

nhiroki@chromium.org changed reviewers:
+ falken@chromium.org

[nhiroki, 2015-04-24 04:03:40]

PTAL

[falken, 2015-04-24 04:14:00]

Looks good, that function was nuts. Should we update callsites that are
unnecessarily doing .get() to pass a raw pointer instead of a ref ptr?

[nhiroki, 2015-04-24 04:38:27]

On 2015/04/24 04:14:00, falken wrote:
> Looks good, that function was nuts. Should we update callsites that are
> unnecessarily doing .get() to pass a raw pointer instead of a ref ptr?

Thank you! Updated.

[falken, 2015-04-24 04:45:39]

Actually should we just make this take a const scoped_refptr& to avoid refcount
churn? I think most of our codebase does that.

Sorry for not thinking of it in the first round.

[nhiroki, 2015-04-24 05:26:10]

On 2015/04/24 04:45:39, falken wrote:
> Actually should we just make this take a const scoped_refptr& to avoid
refcount
> churn? I think most of our codebase does that.
> 
> Sorry for not thinking of it in the first round.

Good point! Updated. Can you take another look?

[falken, 2015-04-24 05:33:21]

lgtm

[nhiroki, 2015-04-24 05:46:54]

The CQ bit was checked by nhiroki@chromium.org

[commit-bot: I haz the power, 2015-04-24 05:47:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1106723002/40001

[commit-bot: I haz the power, 2015-04-24 07:38:22]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-04-24 07:39:12]

Patchset 3 (id:??) landed as
https://crrev.com/964b57ac5be1001f57dfb03262454324ef8b173a
Cr-Commit-Position: refs/heads/master@{#326753}