The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/051a90313eb6f6851bb463e415d73d8556d3366d

commit 051a90313eb6f6851bb463e415d73d8556d3366d
Author: bashi <bashi@chromium.org>
Date: Tue Nov 08 04:13:55 2016

Add StateOn{Moderate,Critical}NotificationReceived metrics

Record the global state of memory coordinator when memory pressure
notification is received. The purpose of this metrics is to make
sure the memory coordinator changes its global state to THROTTLED
or SUSPENDED before receiving memory pressure notifications.

BUG= 662772 

Review-Url: https://codereview.chromium.org/2482783002
Cr-Commit-Position: refs/heads/master@{#430517}

[modify] https://crrev.com/051a90313eb6f6851bb463e415d73d8556d3366d/base/memory/memory_coordinator_client.h
[modify] https://crrev.com/051a90313eb6f6851bb463e415d73d8556d3366d/content/browser/browser_main_loop.cc
[modify] https://crrev.com/051a90313eb6f6851bb463e415d73d8556d3366d/content/browser/memory/memory_coordinator.cc
[modify] https://crrev.com/051a90313eb6f6851bb463e415d73d8556d3366d/content/browser/memory/memory_coordinator.h
[modify] https://crrev.com/051a90313eb6f6851bb463e415d73d8556d3366d/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d3bec15af939d0841149aa0f24e1816e586dd47a

commit d3bec15af939d0841149aa0f24e1816e586dd47a
Author: bashi <bashi@chromium.org>
Date: Thu Nov 10 03:14:52 2016

Add Memory.Coordinator.FreeMemoryUntilCritical UMA

Report free memory until the system enters critical state.

Design doc: https://docs.google.com/document/d/1Mlx7q_8thkoQtg_C7-CNA_y0SxSK0yp_ja9Zs4HmcwU/edit#heading=h.92zih6k89h8i

BUG= 662772 

Review-Url: https://codereview.chromium.org/2482863003
Cr-Commit-Position: refs/heads/master@{#431160}

[modify] https://crrev.com/d3bec15af939d0841149aa0f24e1816e586dd47a/content/browser/memory/memory_coordinator_impl.cc
[modify] https://crrev.com/d3bec15af939d0841149aa0f24e1816e586dd47a/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d351969bdb53d2ecf8f61db2987280a826cca738

commit d351969bdb53d2ecf8f61db2987280a826cca738
Author: bashi <bashi@chromium.org>
Date: Thu Nov 10 05:17:58 2016

memory coordinator: Add metrics for Android's onTrimMemory()

Record levels of onTrimMemory()[1]. Define separate histograms for each
memory state so that we can examine the behavior of the memory
coordinator. For example, the number of onTrimMemory() calls should be
smaller in NORMAL state than THROTTLED/SUSPENDED states.

[1]
https://developer.android.com/reference/android/content/ComponentCallbacks2.html#onTrimMemory(int)

Design doc:
https://docs.google.com/document/d/1Mlx7q_8thkoQtg_C7-CNA_y0SxSK0yp_ja9Zs4HmcwU/edit#heading=h.7g1az9n5ec1m

BUG= 662772 

Review-Url: https://codereview.chromium.org/2486573003
Cr-Commit-Position: refs/heads/master@{#431188}

[modify] https://crrev.com/d351969bdb53d2ecf8f61db2987280a826cca738/content/browser/memory/memory_monitor_android.cc
[modify] https://crrev.com/d351969bdb53d2ecf8f61db2987280a826cca738/content/public/android/java/src/org/chromium/content/browser/MemoryMonitorAndroid.java
[modify] https://crrev.com/d351969bdb53d2ecf8f61db2987280a826cca738/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3e7b2c2e9ad184a7e541f3eb1a30b9db34408f7a

commit 3e7b2c2e9ad184a7e541f3eb1a30b9db34408f7a
Author: bashi <bashi@chromium.org>
Date: Sat Nov 12 00:34:25 2016

Add metrics for memory coordinator global state change

Record some metrics when the memory coordinator changes its global
state. Added metrics are:
- Total private working set memory of the browser/renderers
- Elapsed time between state changes

Design doc: https://docs.google.com/document/d/1Mlx7q_8thkoQtg_C7-CNA_y0SxSK0yp_ja9Zs4HmcwU/edit?usp=sharing

BUG= 662772 

Review-Url: https://codereview.chromium.org/2476223002
Cr-Commit-Position: refs/heads/master@{#431709}

[modify] https://crrev.com/3e7b2c2e9ad184a7e541f3eb1a30b9db34408f7a/content/browser/memory/memory_coordinator_impl.cc
[modify] https://crrev.com/3e7b2c2e9ad184a7e541f3eb1a30b9db34408f7a/content/browser/memory/memory_coordinator_impl.h
[modify] https://crrev.com/3e7b2c2e9ad184a7e541f3eb1a30b9db34408f7a/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5e2c875dca161e2b897d4cf454633c424b52f55b

commit 5e2c875dca161e2b897d4cf454633c424b52f55b
Author: bashi <bashi@chromium.org>
Date: Fri Dec 02 07:05:40 2016

Add MemoryCoordinator::GetGlobalMemoryState()

MemoryCoordinator::GetCurrentMemoryState() is not always the same as
the global memory state because the browser process won't be suspended
(at least for now). On the other hand, we want to have a way to record
the global memory state to tweak memory coordinator's parameters.
Add GetGlobalMemoryState() method which returns the raw value of the
global state. Keep GetCurrentMemoryState() for clients in the browser
process.

BUG= 662772 

Review-Url: https://codereview.chromium.org/2550623002
Cr-Commit-Position: refs/heads/master@{#435873}

[modify] https://crrev.com/5e2c875dca161e2b897d4cf454633c424b52f55b/content/browser/memory/memory_coordinator.cc
[modify] https://crrev.com/5e2c875dca161e2b897d4cf454633c424b52f55b/content/browser/memory/memory_coordinator.h
[modify] https://crrev.com/5e2c875dca161e2b897d4cf454633c424b52f55b/content/browser/memory/memory_coordinator_impl.cc
[modify] https://crrev.com/5e2c875dca161e2b897d4cf454633c424b52f55b/content/browser/memory/memory_coordinator_impl.h
[modify] https://crrev.com/5e2c875dca161e2b897d4cf454633c424b52f55b/content/browser/memory/memory_monitor_android.cc

Many metrics I added weren't very helpful. I'm going to deprecate most of them.