Revert of Make MappedFile (aka OnDisk) the default for persistent histograms.

Revert of Make MappedFile (aka OnDisk) the default for persistent histograms. (patchset #2 id:20001 of https://codereview.chromium.org/2647353003/ )

Reason for revert:
This patch breaks the chrome-pfq build with errors: https://bugs.chromium.org/p/chromium/issues/detail?id=674209, a sample auto-bug is: https://bugs.chromium.org/p/chromium/issues/detail?id=684212

Original issue's description:
> Make MappedFile (aka OnDisk) the default for persistent histograms.
> 
> BUG=583440
> 
> Review-Url: https://codereview.chromium.org/2647353003
> Cr-Commit-Position: refs/heads/master@{#445516}
> Committed: https://chromium.googlesource.com/chromium/src/+/ba68aeb47c44cb7ccc9b1e1cab35cc032556dfe6

TBR=asvitkine@chromium.org,bcwhite@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=583440
Review-Url: https://codereview.chromium.org/2649973007
Cr-Commit-Position: refs/heads/master@{#445992}
Committed: https://chromium.googlesource.com/chromium/src/+/7ca1c566e7af0996087c949dae38bfc7af908a37

[Qiang(Joe) Xu, 2017-01-25 05:59:46]

The CQ bit was checked by warx@chromium.org

[Qiang(Joe) Xu, 2017-01-25 05:59:47]

Created Revert of Make MappedFile (aka OnDisk) the default for persistent
histograms.

[commit-bot: I haz the power, 2017-01-25 06:00:02]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-01-25 10:14:32]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1485323986876340, "parent_rev":
"9756a18af5acb7fcc5f674b7908d9daeaf3357ba", "commit_rev":
"7ca1c566e7af0996087c949dae38bfc7af908a37"}

[commit-bot: I haz the power, 2017-01-25 10:15:02]

Description was changed from

==========
Revert of Make MappedFile (aka OnDisk) the default for persistent histograms.
(patchset #2 id:20001 of https://codereview.chromium.org/2647353003/ )

Reason for revert:
This patch breaks the chrome-pfq build with errors:
https://bugs.chromium.org/p/chromium/issues/detail?id=674209, a sample auto-bug
is: https://bugs.chromium.org/p/chromium/issues/detail?id=684212

Original issue's description:
> Make MappedFile (aka OnDisk) the default for persistent histograms.
> 
> BUG=583440
> 
> Review-Url: https://codereview.chromium.org/2647353003
> Cr-Commit-Position: refs/heads/master@{#445516}
> Committed:
https://chromium.googlesource.com/chromium/src/+/ba68aeb47c44cb7ccc9b1e1cab35...

TBR=asvitkine@chromium.org,bcwhite@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=583440
==========

to

==========
Revert of Make MappedFile (aka OnDisk) the default for persistent histograms.
(patchset #2 id:20001 of https://codereview.chromium.org/2647353003/ )

Reason for revert:
This patch breaks the chrome-pfq build with errors:
https://bugs.chromium.org/p/chromium/issues/detail?id=674209, a sample auto-bug
is: https://bugs.chromium.org/p/chromium/issues/detail?id=684212

Original issue's description:
> Make MappedFile (aka OnDisk) the default for persistent histograms.
> 
> BUG=583440
> 
> Review-Url: https://codereview.chromium.org/2647353003
> Cr-Commit-Position: refs/heads/master@{#445516}
> Committed:
https://chromium.googlesource.com/chromium/src/+/ba68aeb47c44cb7ccc9b1e1cab35...

TBR=asvitkine@chromium.org,bcwhite@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=583440

Review-Url: https://codereview.chromium.org/2649973007
Cr-Commit-Position: refs/heads/master@{#445992}
Committed:
https://chromium.googlesource.com/chromium/src/+/7ca1c566e7af0996087c949dae38...
==========

[commit-bot: I haz the power, 2017-01-25 10:15:03]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/7ca1c566e7af0996087c949dae38...

[bcwhite, 2017-01-25 13:19:57]

Before you created the revert, did you try the solution on the original CL?

IF YOUR TEST IS FAILING because of this CL then it's likely trying to read the
contents of histograms set by sub-processes.

Try calling SubprocessMetricsProvider::MergeHistogramDeltasForTesting() before
checking histogram counts to see if that gets the results you want.

[Qiang(Joe) Xu, 2017-01-25 18:32:45]

On 2017/01/25 13:19:57, bcwhite wrote:
> Before you created the revert, did you try the solution on the original CL?
> 
> IF YOUR TEST IS FAILING because of this CL then it's likely trying to read the
> contents of histograms set by sub-processes.
> 
> Try calling SubprocessMetricsProvider::MergeHistogramDeltasForTesting() before
> checking histogram counts to see if that gets the results you want.

ChromeHWDecodeUsed is a chromeos autotest. I should contact the people who are
working on this.
Just a friendly reminder, please do not reland this CL until we fix the autotest
issue. thanks

[bcwhite, 2017-01-25 19:15:09]

On 2017/01/25 18:32:45, Qiang(Joe) Xu wrote:
> On 2017/01/25 13:19:57, bcwhite wrote:
> > Before you created the revert, did you try the solution on the original CL?
> > 
> > IF YOUR TEST IS FAILING because of this CL then it's likely trying to read
the
> > contents of histograms set by sub-processes.
> > 
> > Try calling SubprocessMetricsProvider::MergeHistogramDeltasForTesting()
before
> > checking histogram counts to see if that gets the results you want.
> 
> ChromeHWDecodeUsed is a chromeos autotest. I should contact the people who are
> working on this.
> Just a friendly reminder, please do not reland this CL until we fix the
autotest
> issue. thanks

Certainly.  Let me know if I can help.