REGRESSION(r157081): Fix multipart handling of ResourceFetcher

REGRESSION(r157081): Fix multipart handling of ResourceFetcher

r157081 broke multipart handling in ResourceFetcher.
The breakage was harmless except Motion JPEG case - ResourceFetcher
lost the reference to Motion JPEG resource so it was no longer
able to cancel the ongoing resource fetching.

This change makes the tracking working again.
Also, the change adds a stopFetching() call to DocumentLoder::stopLoading()
that is used to be there but was lost at some point.

TEST=stop-loading.html
R=japhet@chromium.org,abarth@chromium.org
BUG=309641
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=171969

[Hajime Morrita, 2014-04-18 00:36:22]

PTAL?

[Hajime Morrita, 2014-04-18 18:03:22]

Hey Nate, could you take a look? This fixes a silly mistake I made in
ResourceFetcher :-/

[Nate Chapin, 2014-04-18 18:10:29]

LGTM with a question

https://codereview.chromium.org/242373002/diff/1/Source/core/loader/DocumentL...
File Source/core/loader/DocumentLoader.cpp (right):

https://codereview.chromium.org/242373002/diff/1/Source/core/loader/DocumentL...
Source/core/loader/DocumentLoader.cpp:193: m_fetcher->stopFetching();
Is the ordering of this call important? If not, I'd favor moving this
stopFetching() call above this if() block and removing the stopFetching() call
at the end of the function.

[Hajime Morrita, 2014-04-18 18:15:27]

Thanks for the review!
 
>
https://codereview.chromium.org/242373002/diff/1/Source/core/loader/DocumentL...
> Source/core/loader/DocumentLoader.cpp:193: m_fetcher->stopFetching();
> Is the ordering of this call important? If not, I'd favor moving this
> stopFetching() call above this if() block and removing the stopFetching() call
> at the end of the function.

I don't know. This change just tries to follow what the old code did.
Will try to move it and see if tests pass.

[Hajime Morrita, 2014-04-18 18:54:35]

The CQ bit was checked by morrita@chromium.org

[commit-bot: I haz the power, 2014-04-18 18:54:52]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/morrita@chromium.org/242373002/20001

[commit-bot: I haz the power, 2014-04-18 20:06:39]

Change committed as 171969