[Merge M48] Add Startup.TimeSinceLastStartup histogram.

[Merge M48] Add Startup.TimeSinceLastStartup histogram.

This histogram shows the time between 2 consecutive startups.

BUG=547794
Review URL: https://codereview.chromium.org/1558203003

Cr-Commit-Position: refs/heads/master@{#368354}
(cherry picked from commit 44cd7819dc6be0e640b6a1e03964d61210415a12)

Conflicts:
	components/startup_metric_utils.gypi
	components/startup_metric_utils/browser/BUILD.gn
	components/startup_metric_utils/browser/startup_metric_utils.cc
	components/startup_metric_utils/browser/startup_metric_utils.h
	tools/metrics/histograms/histograms.xml

R=fdoray@chromium.org
TBR=fdoray@chromium.org

Committed: https://chromium.googlesource.com/chromium/src/+/d76590e3f0096e1ddb59b518abde53d0cda8d5a0

[gab, 2016-02-03 20:24:36]

Patchset #1 (id:1) has been deleted

[gab, 2016-02-03 20:34:02]

gab@chromium.org changed reviewers:
+ fdoray@chromium.org

[gab, 2016-02-03 20:34:02]

Planned merges to M48 -- @fdoray PTAL.

[fdoray, 2016-02-03 20:42:51]

lgtm

[gab, 2016-02-04 00:13:52]

Description was changed from

==========
[Merge M48] Add Startup.TimeSinceLastStartup histogram.

This histogram shows the time between 2 consecutive startups.

BUG=547794

Review URL: https://codereview.chromium.org/1558203003

Cr-Commit-Position: refs/heads/master@{#368354}
(cherry picked from commit 44cd7819dc6be0e640b6a1e03964d61210415a12)

Conflicts:
	components/startup_metric_utils.gypi
	components/startup_metric_utils/browser/BUILD.gn
	components/startup_metric_utils/browser/startup_metric_utils.cc
	components/startup_metric_utils/browser/startup_metric_utils.h
	tools/metrics/histograms/histograms.xml
==========

to

==========
[Merge M48] Add Startup.TimeSinceLastStartup histogram.

This histogram shows the time between 2 consecutive startups.

BUG=547794

Review URL: https://codereview.chromium.org/1558203003

Cr-Commit-Position: refs/heads/master@{#368354}
(cherry picked from commit 44cd7819dc6be0e640b6a1e03964d61210415a12)

Conflicts:
	components/startup_metric_utils.gypi
	components/startup_metric_utils/browser/BUILD.gn
	components/startup_metric_utils/browser/startup_metric_utils.cc
	components/startup_metric_utils/browser/startup_metric_utils.h
	tools/metrics/histograms/histograms.xml

TBR=fdoray@chromium.org
==========

[gab, 2016-02-04 01:09:04]

Description was changed from

==========
[Merge M48] Add Startup.TimeSinceLastStartup histogram.

This histogram shows the time between 2 consecutive startups.

BUG=547794

Review URL: https://codereview.chromium.org/1558203003

Cr-Commit-Position: refs/heads/master@{#368354}
(cherry picked from commit 44cd7819dc6be0e640b6a1e03964d61210415a12)

Conflicts:
	components/startup_metric_utils.gypi
	components/startup_metric_utils/browser/BUILD.gn
	components/startup_metric_utils/browser/startup_metric_utils.cc
	components/startup_metric_utils/browser/startup_metric_utils.h
	tools/metrics/histograms/histograms.xml

TBR=fdoray@chromium.org
==========

to

==========
[Merge M48] Add Startup.TimeSinceLastStartup histogram.

This histogram shows the time between 2 consecutive startups.

BUG=547794

Review URL: https://codereview.chromium.org/1558203003

Cr-Commit-Position: refs/heads/master@{#368354}
(cherry picked from commit 44cd7819dc6be0e640b6a1e03964d61210415a12)

Conflicts:
	components/startup_metric_utils.gypi
	components/startup_metric_utils/browser/BUILD.gn
	components/startup_metric_utils/browser/startup_metric_utils.cc
	components/startup_metric_utils/browser/startup_metric_utils.h
	tools/metrics/histograms/histograms.xml

R=fdoray@chromium.org
TBR=fdoray@chromium.org

Committed:
https://chromium.googlesource.com/chromium/src/+/d76590e3f0096e1ddb59b518abde...
==========

[gab, 2016-02-04 01:09:05]

Committed patchset #1 (id:20001) manually as
d76590e3f0096e1ddb59b518abde53d0cda8d5a0 (presubmit successful).