As a related aside: We should not enable profiling if there exist any incognito sessions. If profiling has already been enabled, we should ensure that no traces/heap_dumps are uploaded if an incognito session exists [at least for slow reports integration. Maybe we want different behavior for explicitly enabled from chrome://flags?]

I'm confused at the incognito session exclusion. Do you mean we shouldn't
profile any renderers for an incognito session? Or do you mean we need to
disable the browser and gpu logging too?

wdyt of this:
1) If any incognito session is active, do not begin any new profiling.
2) If any incognito session is active, do not trigger any slow report uploads.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1cdbbcd0352cc9f306aaeba3460f1a4988da3575

commit 1cdbbcd0352cc9f306aaeba3460f1a4988da3575
Author: Albert J. Wong <ajwong@chromium.org>
Date: Tue Nov 07 22:28:53 2017

OOPHP: Add 3 new modes of process profiling.

The new modes are
  Browser process only
  Gpu process only
  RendererSampling (semi-randomly samples a single renderer process in a chrome run).

Bug:  777984 
Change-Id: Ibb78d516450a23e35e2195a85b35ff87f565bb7a
Reviewed-on: https://chromium-review.googlesource.com/742227
Commit-Queue: Albert J. Wong <ajwong@chromium.org>
Reviewed-by: Brett Wilson <brettw@chromium.org>
Reviewed-by: Albert J. Wong <ajwong@chromium.org>
Reviewed-by: Erik Chen <erikchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#514621}
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/browser/about_flags.cc
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/browser/profiling_host/background_profiling_triggers.cc
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/browser/profiling_host/background_profiling_triggers.h
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/browser/profiling_host/background_profiling_triggers_unittest.cc
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/browser/profiling_host/memlog_browsertest.cc
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/browser/profiling_host/profiling_process_host.cc
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/browser/profiling_host/profiling_process_host.h
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/browser/ui/webui/memory_internals_ui.cc
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/common/chrome_switches.cc
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/common/chrome_switches.h
[modify] https://crrev.com/1cdbbcd0352cc9f306aaeba3460f1a4988da3575/chrome/profiling/memlog_connection_manager.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/71b8cd21499f56192cad4d32ed6b0cd655c1c597

commit 71b8cd21499f56192cad4d32ed6b0cd655c1c597
Author: Scott Violet <sky@chromium.org>
Date: Wed Nov 08 01:00:25 2017

Revert "OOPHP: Add 3 new modes of process profiling."

This reverts commit 1cdbbcd0352cc9f306aaeba3460f1a4988da3575.

Reason for revert: New test is failing on bot. See https://chromium-swarm.appspot.com/task?id=39b1aaa7f7108b10&refresh=10&show_raw=1&wide_logs=true output:

[ RUN      ] RendererSampling/MemlogBrowserTest.EndToEnd/0
Xlib:  extension "RANDR" missing on display ":99".
[6807:6842:1107/154805.447718:ERROR:bus.cc(395)] Failed to connect to the bus: Could not parse server address: Unknown address type (examples of valid types are "tcp" and on UNIX "unix")
[6807:6807:1107/154805.453384:WARNING:password_store_factory.cc(241)] Using basic (unencrypted) store for password storage. See https://chromium.googlesource.com/chromium/src/+/master/docs/linux_password_storage.md for more information about password storage options.
[6807:6835:1107/154805.457621:ERROR:service_manager.cc(158)] Connection InterfaceProviderSpec prevented service: content_browser from binding interface: resource_coordinator::mojom::PageSignalGenerator exposed by: resource_coordinator
[6807:6889:1107/154806.090906:WARNING:embedded_test_server.cc(228)] Request not handled. Returning 404: /favicon.ico
[6807:6807:1107/154806.183391:ERROR:memlog_browsertest.cc(278)] Cannot open compressed trace file
../../chrome/browser/profiling_host/memlog_browsertest.cc:380: Failure
Value of: dump_json
  Actual: true
Expected: false
Renderer process unexpectedly profiled.
[6807:6807:1107/154806.233010:INFO:chrome_cryptauth_service.cc(222)] Profile is not authenticated yet; waiting before starting CryptAuth managers.
[  FAILED  ] RendererSampling/MemlogBrowserTest.EndToEnd/0, where GetParam() = "renderer-sampling" (1447 ms)

Original change's description:
> OOPHP: Add 3 new modes of process profiling.
> 
> The new modes are
>   Browser process only
>   Gpu process only
>   RendererSampling (semi-randomly samples a single renderer process in a chrome run).
> 
> Bug:  777984 
> Change-Id: Ibb78d516450a23e35e2195a85b35ff87f565bb7a
> Reviewed-on: https://chromium-review.googlesource.com/742227
> Commit-Queue: Albert J. Wong <ajwong@chromium.org>
> Reviewed-by: Brett Wilson <brettw@chromium.org>
> Reviewed-by: Albert J. Wong <ajwong@chromium.org>
> Reviewed-by: Erik Chen <erikchen@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#514621}

TBR=ajwong@chromium.org,brettw@chromium.org,erikchen@chromium.org

Change-Id: I5e351ac4c7f001a317654de367a79087064d4d40
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  777984 
Reviewed-on: https://chromium-review.googlesource.com/757996
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#514689}
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/browser/about_flags.cc
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/browser/profiling_host/background_profiling_triggers.cc
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/browser/profiling_host/background_profiling_triggers.h
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/browser/profiling_host/background_profiling_triggers_unittest.cc
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/browser/profiling_host/memlog_browsertest.cc
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/browser/profiling_host/profiling_process_host.cc
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/browser/profiling_host/profiling_process_host.h
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/browser/ui/webui/memory_internals_ui.cc
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/common/chrome_switches.cc
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/common/chrome_switches.h
[modify] https://crrev.com/71b8cd21499f56192cad4d32ed6b0cd655c1c597/chrome/profiling/memlog_connection_manager.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bd5bd90ca753c5faed4e755d361754fa75195176

commit bd5bd90ca753c5faed4e755d361754fa75195176
Author: Albert J. Wong <ajwong@chromium.org>
Date: Thu Nov 09 19:56:15 2017

Reland: OOPHP:Add 3 new modes of process profiling

Original CL: https://chromium-review.googlesource.com/742227

Renderer Sampling mode was causing tests to be non-deterministic. This
adds an override method that test can use to make the sampling be 100%
which is deterministic.

Bug:  780955 ,  777984 
Change-Id: I239654ebd41fc51227b257525008f62322ff8318
TBR: brettw,erikchen
Reviewed-on: https://chromium-review.googlesource.com/758490
Commit-Queue: Albert J. Wong <ajwong@chromium.org>
Reviewed-by: Albert J. Wong <ajwong@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515252}
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/browser/about_flags.cc
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/browser/profiling_host/background_profiling_triggers.cc
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/browser/profiling_host/background_profiling_triggers.h
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/browser/profiling_host/background_profiling_triggers_unittest.cc
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/browser/profiling_host/memlog_browsertest.cc
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/browser/profiling_host/profiling_process_host.cc
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/browser/profiling_host/profiling_process_host.h
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/browser/ui/webui/memory_internals_ui.cc
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/common/chrome_switches.cc
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/common/chrome_switches.h
[modify] https://crrev.com/bd5bd90ca753c5faed4e755d361754fa75195176/chrome/profiling/memlog_connection_manager.cc

These have landed. Closing.