Shifted DownloadFile to exporting DownloadInterruptReasons.

Shifted DownloadFile to exporting DownloadInterruptReasons.

DownloadFile used to return net::Errors (as BaseFile does).  With the 
folding of functionality from the DownloadFileManager implied by 
the ByteStream refactor (the DownloadFile gives completion messages
directly to the DownloadManager), it exported some DownloadInterruptReasons.
This CL takes it the rest of the way.

BUG=123998
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=145376

[Randy Smith (Not in Mondays), 2012-06-29 03:06:34]

Ben: I've been asking Asanka for a lot of reviews recently, so I'm going to
throw a couple your way.  PTAL?

[benjhayden, 2012-06-29 15:57:21]

lgtm

[commit-bot: I haz the power, 2012-07-02 15:44:20]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rdsmith@chromium.org/10696043/1

[commit-bot: I haz the power, 2012-07-02 15:44:23]

Failed to apply patch for content/browser/download/download_file_manager.cc:
While running patch -p1 --forward --force;
patching file content/browser/download/download_file_manager.cc
Hunk #2 FAILED at 212.
Hunk #3 FAILED at 224.
2 out of 3 hunks FAILED -- saving rejects to file
content/browser/download/download_file_manager.cc.rej

[commit-bot: I haz the power, 2012-07-02 20:17:16]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rdsmith@chromium.org/10696043/9001

[commit-bot: I haz the power, 2012-07-02 20:17:23]

Presubmit check for 10696043-9001 failed and returned exit status 1.

Running presubmit commit checks ...

** Presubmit Messages **
If this change requires manual test instructions to QA team, add
TEST=[instructions].

** Presubmit ERRORS **
Missing LGTM from an OWNER for files in these directories:
    content/test
    content/public/test

Presubmit checks took 1.1s to calculate.

[Randy Smith (Not in Mondays), 2012-07-02 20:33:05]

Sky, Rubbertamp?

[Randy Smith (Not in Mondays), 2012-07-03 15:29:06]

I think Scott's on vacation.  Jay, can I get a rubberstamp for the test
directories from you?

[Jay Civelli, 2012-07-03 17:13:25]

lgtm

[commit-bot: I haz the power, 2012-07-03 17:22:52]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rdsmith@chromium.org/10696043/9001

[commit-bot: I haz the power, 2012-07-03 17:22:57]

Failed to apply patch for content/browser/download/download_file_impl.cc:
While running patch -p1 --forward --force;
patching file content/browser/download/download_file_impl.cc
Hunk #4 FAILED at 188.
1 out of 4 hunks FAILED -- saving rejects to file
content/browser/download/download_file_impl.cc.rej

[commit-bot: I haz the power, 2012-07-03 17:57:09]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rdsmith@chromium.org/10696043/1013

[commit-bot: I haz the power, 2012-07-03 17:57:20]

Failed to apply patch for content/browser/download/download_file_impl.cc:
While running patch -p1 --forward --force;
patching file content/browser/download/download_file_impl.cc
Hunk #4 FAILED at 188.
1 out of 4 hunks FAILED -- saving rejects to file
content/browser/download/download_file_impl.cc.rej

[commit-bot: I haz the power, 2012-07-03 18:10:08]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rdsmith@chromium.org/10696043/9002

[commit-bot: I haz the power, 2012-07-03 18:55:54]

Try job failure for 10696043-9002 (retry) on linux_rel for step
"interactive_ui_tests".
It's a second try, previously, step "interactive_ui_tests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...

[commit-bot: I haz the power, 2012-07-03 19:42:32]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rdsmith@chromium.org/10696043/9002

[commit-bot: I haz the power, 2012-07-03 20:47:41]

Change committed as 145376