Upstream RunBlockingPoolTask().

Upstream RunBlockingPoolTask().

This routine used to be used by Drive tests only. However, File System Provider
API code would also like to take advantage of it.

Note, that this function should be used in tens of other places in Chromium
code base, instead SequencedWorkerPool::FlushForTesting() more than once if
several rounds of posting tasks to the blocking pool may happen.

TEST=Refactoring only. Compiles and passes all current tests.
BUG=392716
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=283333

[mtomasz, 2014-07-10 05:00:24]

@hashimoto: PTAL. Thanks.

[hashimoto, 2014-07-11 05:38:19]

I'm not sure if we should put this in content.
It's generally discouraged to use real threads for testing.
(https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/qQiWjlxRcE4)

Please ask content owners for it.

[mtomasz, 2014-07-11 06:26:48]

This utility method should be used with TestBrowserThreadBundle. I don't think
we have a way to mock out the blocking pool for unit tests.

+@sky: PTAL at content/public/test/*
+cc @kalman, who was interested in this.

[sky, 2014-07-11 16:37:54]

https://codereview.chromium.org/380993002/diff/1/content/public/test/test_uti...
File content/public/test/test_utils.cc (right):

https://codereview.chromium.org/380993002/diff/1/content/public/test/test_uti...
content/public/test/test_utils.cc:157: TaskObserver task_observer;
It seems like you want to know if any tasks are added while flushing the
blocking pool. I would have expected the TaskObserver to be added before the
flush.

https://codereview.chromium.org/380993002/diff/1/content/public/test/test_uti...
File content/public/test/test_utils.h (right):

https://codereview.chromium.org/380993002/diff/1/content/public/test/test_uti...
content/public/test/test_utils.h:47: // Runs all tasks posted to the blocking
pool, including subsequent tasks posted
You're description seems overly complicated, maybe:
Runs until both the blocking pool and the current message loop are empty (have
no more scheduled tasks).

[mtomasz, 2014-07-14 07:33:57]

https://codereview.chromium.org/380993002/diff/1/content/public/test/test_uti...
File content/public/test/test_utils.cc (right):

https://codereview.chromium.org/380993002/diff/1/content/public/test/test_uti...
content/public/test/test_utils.cc:157: TaskObserver task_observer;
On 2014/07/11 16:37:54, sky wrote:
> It seems like you want to know if any tasks are added while flushing the
> blocking pool. I would have expected the TaskObserver to be added before the
> flush.

Done.

https://codereview.chromium.org/380993002/diff/1/content/public/test/test_uti...
File content/public/test/test_utils.h (right):

https://codereview.chromium.org/380993002/diff/1/content/public/test/test_uti...
content/public/test/test_utils.h:47: // Runs all tasks posted to the blocking
pool, including subsequent tasks posted
On 2014/07/11 16:37:54, sky wrote:
> You're description seems overly complicated, maybe:
> Runs until both the blocking pool and the current message loop are empty (have
> no more scheduled tasks).

Done.

[sky, 2014-07-14 17:11:19]

LGTM

[mtomasz, 2014-07-14 23:11:32]

On 2014/07/14 17:11:19, sky wrote:
> LGTM

@hashimoto: PTAL at changes in drive code. Thanks.

[hashimoto, 2014-07-15 05:17:41]

https://codereview.chromium.org/380993002/diff/1/content/public/test/test_uti...
File content/public/test/test_utils.cc (right):

https://codereview.chromium.org/380993002/diff/1/content/public/test/test_uti...
content/public/test/test_utils.cc:157: TaskObserver task_observer;
On 2014/07/14 07:33:57, mtomasz wrote:
> On 2014/07/11 16:37:54, sky wrote:
> > It seems like you want to know if any tasks are added while flushing the
> > blocking pool. I would have expected the TaskObserver to be added before the
> > flush.
> 
> Done.

No need to start observing the message loop while flushing the blocking pool.
The observer is not to know if any tasks are added while flushing.
task_observer.posted() returns true if the message loop processes any tasks
during RunUntilIdle().

Perhaps, we should rename posted() to something like "processed_any_task" to
make it clear.

https://codereview.chromium.org/380993002/diff/20001/chrome/browser/chromeos/...
File chrome/browser/chromeos/drive/fake_file_system_unittest.cc (right):

https://codereview.chromium.org/380993002/diff/20001/chrome/browser/chromeos/...
chrome/browser/chromeos/drive/fake_file_system_unittest.cc:13: #include
"content/public/test/test_utils.h"
nit: Is this include needed?

[mtomasz, 2014-07-15 05:45:30]

https://codereview.chromium.org/380993002/diff/1/content/public/test/test_uti...
File content/public/test/test_utils.cc (right):

https://codereview.chromium.org/380993002/diff/1/content/public/test/test_uti...
content/public/test/test_utils.cc:157: TaskObserver task_observer;
On 2014/07/15 05:17:41, hashimoto wrote:
> On 2014/07/14 07:33:57, mtomasz wrote:
> > On 2014/07/11 16:37:54, sky wrote:
> > > It seems like you want to know if any tasks are added while flushing the
> > > blocking pool. I would have expected the TaskObserver to be added before
the
> > > flush.
> > 
> > Done.
> 
> No need to start observing the message loop while flushing the blocking pool.
> The observer is not to know if any tasks are added while flushing.
> task_observer.posted() returns true if the message loop processes any tasks
> during RunUntilIdle().
> 
> Perhaps, we should rename posted() to something like "processed_any_task" to
> make it clear.

Done.

https://codereview.chromium.org/380993002/diff/20001/chrome/browser/chromeos/...
File chrome/browser/chromeos/drive/fake_file_system_unittest.cc (right):

https://codereview.chromium.org/380993002/diff/20001/chrome/browser/chromeos/...
chrome/browser/chromeos/drive/fake_file_system_unittest.cc:13: #include
"content/public/test/test_utils.h"
On 2014/07/15 05:17:41, hashimoto wrote:
> nit: Is this include needed?

Done.

[hashimoto, 2014-07-15 05:49:40]

https://codereview.chromium.org/380993002/diff/20001/chrome/browser/chromeos/...
File chrome/browser/chromeos/drive/fake_file_system_unittest.cc (right):

https://codereview.chromium.org/380993002/diff/20001/chrome/browser/chromeos/...
chrome/browser/chromeos/drive/fake_file_system_unittest.cc:13: #include
"content/public/test/test_utils.h"
On 2014/07/15 05:45:29, mtomasz wrote:
> On 2014/07/15 05:17:41, hashimoto wrote:
> > nit: Is this include needed?
> 
> Done.

What have you done?

https://codereview.chromium.org/380993002/diff/40001/content/public/test/test...
File content/public/test/test_utils.cc (right):

https://codereview.chromium.org/380993002/diff/40001/content/public/test/test...
content/public/test/test_utils.cc:155: TaskObserver task_observer;
nit: task_observer should be declared and initialized just before
AddTaskObserver().

[mtomasz, 2014-07-15 05:59:16]

https://codereview.chromium.org/380993002/diff/20001/chrome/browser/chromeos/...
File chrome/browser/chromeos/drive/fake_file_system_unittest.cc (right):

https://codereview.chromium.org/380993002/diff/20001/chrome/browser/chromeos/...
chrome/browser/chromeos/drive/fake_file_system_unittest.cc:13: #include
"content/public/test/test_utils.h"
On 2014/07/15 05:49:40, hashimoto wrote:
> On 2014/07/15 05:45:29, mtomasz wrote:
> > On 2014/07/15 05:17:41, hashimoto wrote:
> > > nit: Is this include needed?
> > 
> > Done.
> 
> What have you done?

Removed since not needed?

https://codereview.chromium.org/380993002/diff/40001/content/public/test/test...
File content/public/test/test_utils.cc (right):

https://codereview.chromium.org/380993002/diff/40001/content/public/test/test...
content/public/test/test_utils.cc:155: TaskObserver task_observer;
On 2014/07/15 05:49:40, hashimoto wrote:
> nit: task_observer should be declared and initialized just before
> AddTaskObserver().

Done.

[hashimoto, 2014-07-15 06:03:44]

lgtm

https://codereview.chromium.org/380993002/diff/20001/chrome/browser/chromeos/...
File chrome/browser/chromeos/drive/fake_file_system_unittest.cc (right):

https://codereview.chromium.org/380993002/diff/20001/chrome/browser/chromeos/...
chrome/browser/chromeos/drive/fake_file_system_unittest.cc:13: #include
"content/public/test/test_utils.h"
On 2014/07/15 05:59:16, mtomasz wrote:
> On 2014/07/15 05:49:40, hashimoto wrote:
> > On 2014/07/15 05:45:29, mtomasz wrote:
> > > On 2014/07/15 05:17:41, hashimoto wrote:
> > > > nit: Is this include needed?
> > > 
> > > Done.
> > 
> > What have you done?
> 
> Removed since not needed?

Ah, "Delta from patch set" doesn't show anything for this file because this file
is no longer included in this change list.
Thanks

[mtomasz, 2014-07-15 06:04:06]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-07-15 06:05:52]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mtomasz@chromium.org/380993002/80001

[mtomasz, 2014-07-15 08:25:31]

The CQ bit was unchecked by mtomasz@chromium.org

[mtomasz, 2014-07-15 08:25:33]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-07-15 08:26:58]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mtomasz@chromium.org/380993002/80001

[commit-bot: I haz the power, 2014-07-15 18:55:11]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_dbg_triggered_tests on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg_triggered...)
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)

[commit-bot: I haz the power, 2014-07-15 19:30:02]

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

[commit-bot: I haz the power, 2014-07-15 19:30:04]

Try jobs failed on following builders:
  android_dbg_triggered_tests on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg_triggered...)

[mtomasz, 2014-07-16 02:17:58]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-07-16 02:21:18]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mtomasz@chromium.org/380993002/80001

[commit-bot: I haz the power, 2014-07-16 04:32:56]

Change committed as 283333