As in crrev.com/2640823004, should confirm if both of the virtual test suites are needed ("stable" and "origin-trials-features-disabled"). The fact that the expectations are identical for both suites suggest otherwise.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0ac7dd29d6b7537444599db5342de36c8f5c6a69

commit 0ac7dd29d6b7537444599db5342de36c8f5c6a69
Author: chasej <chasej@chromium.org>
Date: Thu Feb 23 18:16:17 2017

Cleanup virtual test suites for origin trials

Remove the 'stable' virtual suite for origin trials layout tests. This
was redundant, as it had the identical expectations as the 'disabled'
virtual suite.

Rename/change the 'disabled' virtual suite to be based strictly on
runtime flags.

BUG= 685788 

Review-Url: https://codereview.chromium.org/2705643002
Cr-Commit-Position: refs/heads/master@{#452552}

[modify] https://crrev.com/0ac7dd29d6b7537444599db5342de36c8f5c6a69/docs/origin_trials_integration.md
[modify] https://crrev.com/0ac7dd29d6b7537444599db5342de36c8f5c6a69/third_party/WebKit/LayoutTests/VirtualTestSuites
[rename] https://crrev.com/0ac7dd29d6b7537444599db5342de36c8f5c6a69/third_party/WebKit/LayoutTests/virtual/origin-trials-runtimeflags-disabled/http/tests/origin_trials/webexposed/README.txt
[rename] https://crrev.com/0ac7dd29d6b7537444599db5342de36c8f5c6a69/third_party/WebKit/LayoutTests/virtual/origin-trials-runtimeflags-disabled/http/tests/origin_trials/webexposed/foreignfetch-origin-trial-interfaces-expected.txt
[rename] https://crrev.com/0ac7dd29d6b7537444599db5342de36c8f5c6a69/third_party/WebKit/LayoutTests/virtual/origin-trials-runtimeflags-disabled/http/tests/origin_trials/webexposed/imagecapture-origin-trial-interfaces-expected.txt
[rename] https://crrev.com/0ac7dd29d6b7537444599db5342de36c8f5c6a69/third_party/WebKit/LayoutTests/virtual/origin-trials-runtimeflags-disabled/http/tests/origin_trials/webexposed/imagecapture-origin-trial-interfaces-script-added-expected.txt
[rename] https://crrev.com/0ac7dd29d6b7537444599db5342de36c8f5c6a69/third_party/WebKit/LayoutTests/virtual/origin-trials-runtimeflags-disabled/http/tests/origin_trials/webexposed/rootscroller-origin-trial-interfaces-expected.txt
[rename] https://crrev.com/0ac7dd29d6b7537444599db5342de36c8f5c6a69/third_party/WebKit/LayoutTests/virtual/origin-trials-runtimeflags-disabled/http/tests/origin_trials/webexposed/rootscroller-origin-trial-interfaces-script-added-expected.txt
[rename] https://crrev.com/0ac7dd29d6b7537444599db5342de36c8f5c6a69/third_party/WebKit/LayoutTests/virtual/origin-trials-runtimeflags-disabled/http/tests/origin_trials/webexposed/webusb-origin-trial-interfaces-expected.txt
[rename] https://crrev.com/0ac7dd29d6b7537444599db5342de36c8f5c6a69/third_party/WebKit/LayoutTests/virtual/origin-trials-runtimeflags-disabled/http/tests/origin_trials/webexposed/webusb-origin-trial-interfaces-script-added-expected.txt
[delete] https://crrev.com/29f1aefe09e181a54a437ab6c2845db8d6463e9b/third_party/WebKit/LayoutTests/virtual/stable/http/tests/origin_trials/webexposed/README.txt
[delete] https://crrev.com/29f1aefe09e181a54a437ab6c2845db8d6463e9b/third_party/WebKit/LayoutTests/virtual/stable/http/tests/origin_trials/webexposed/foreignfetch-origin-trial-interfaces-expected.txt
[delete] https://crrev.com/29f1aefe09e181a54a437ab6c2845db8d6463e9b/third_party/WebKit/LayoutTests/virtual/stable/http/tests/origin_trials/webexposed/imagecapture-origin-trial-interfaces-expected.txt
[delete] https://crrev.com/29f1aefe09e181a54a437ab6c2845db8d6463e9b/third_party/WebKit/LayoutTests/virtual/stable/http/tests/origin_trials/webexposed/imagecapture-origin-trial-interfaces-script-added-expected.txt
[delete] https://crrev.com/29f1aefe09e181a54a437ab6c2845db8d6463e9b/third_party/WebKit/LayoutTests/virtual/stable/http/tests/origin_trials/webexposed/rootscroller-origin-trial-interfaces-expected.txt
[delete] https://crrev.com/29f1aefe09e181a54a437ab6c2845db8d6463e9b/third_party/WebKit/LayoutTests/virtual/stable/http/tests/origin_trials/webexposed/rootscroller-origin-trial-interfaces-script-added-expected.txt
[delete] https://crrev.com/29f1aefe09e181a54a437ab6c2845db8d6463e9b/third_party/WebKit/LayoutTests/virtual/stable/http/tests/origin_trials/webexposed/webusb-origin-trial-interfaces-expected.txt
[delete] https://crrev.com/29f1aefe09e181a54a437ab6c2845db8d6463e9b/third_party/WebKit/LayoutTests/virtual/stable/http/tests/origin_trials/webexposed/webusb-origin-trial-interfaces-script-added-expected.txt

Ideally, we can add a command-line switch without much effort, to simplify the maintenance of tests.

Considerations:
- Probably use code generation to map any command-line switch to features that are under origin trial
- The documentation should be updated as necessary (docs/origin_trials_integration.md)

Isn't --disable-features=OriginTrials sufficient to disable all origin trials?

Looking at TrialTokenValidator::RequestEnablesFeature (https://cs.chromium.org/chromium/src/content/common/origin_trials/trial_token_validator.cc?l=70) ut returns false if OriginTrials is disabled.

Am I misunderstanding the goal?

After chatting offline the purpose is clearer. We want a global flag that will disable all the runtime enabled features that can be enabled via origin trials. This is to allow tests to verify that origin trials is actually doing something and not that the feature happens to be enabled anyway.

My idea then is to add to the generated file gen/blink/platform/RuntimeEnabledFeatures.{h,cpp}
  static blink::RuntimeEnabledFeatures::SetOriginTrialFeaturesEnabled(bool)

and plumbing the flag --disable-all-origin-trial-controlled-features to set this to false.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a240566472914a6dd87070f8ea16e16981e65a1f

commit a240566472914a6dd87070f8ea16e16981e65a1f
Author: Alex Vallée <avallee@google.com>
Date: Fri Jul 14 01:51:27 2017

[OriginTrials] Allow RuntimeEnabledFeatures to be disabled as a block.

For testing, we want to validate that OriginTrials is actually the cause
of the feature being enabled, not that a feature might be enabled by
RuntimeEnabledFeatures (early out).

RuntimeEnabledFeatures::SetOriginTrialControlledFeaturesEnabled allows
you to turn off all the features that can be turned on by OriginTrials.

BUG= 685788 

Change-Id: I7d18673db24b5b90d139b171e3094b66566b693c
Reviewed-on: https://chromium-review.googlesource.com/568368
Reviewed-by: Ian Clelland <iclelland@chromium.org>
Reviewed-by: Jason Chase <chasej@chromium.org>
Commit-Queue: Alex Vallee <avallee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#486621}
[modify] https://crrev.com/a240566472914a6dd87070f8ea16e16981e65a1f/third_party/WebKit/Source/build/scripts/make_runtime_features.py
[modify] https://crrev.com/a240566472914a6dd87070f8ea16e16981e65a1f/third_party/WebKit/Source/build/scripts/templates/RuntimeEnabledFeatures.cpp.tmpl
[modify] https://crrev.com/a240566472914a6dd87070f8ea16e16981e65a1f/third_party/WebKit/Source/build/scripts/templates/RuntimeEnabledFeatures.h.tmpl

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/640aa39844d3f15f8d274f7d9b13a6175d1f1c38

commit 640aa39844d3f15f8d274f7d9b13a6175d1f1c38
Author: Alex Vallée <avallee@google.com>
Date: Sat Jul 15 02:02:14 2017

[OriginTrials] Plumb command-line flag to disable features.

Added --disable-all-origin-trial-controlled-features which will turn off
all RuntimeEnabledFeatures that can be enabled by OT. These features can
then only be enabled with a valid trial token.

Bug:  685788 
Change-Id: Ic5e3976fe51482794107ca82c32412f2b47aee8c
Reviewed-on: https://chromium-review.googlesource.com/568807
Commit-Queue: Alex Vallee <avallee@chromium.org>
Reviewed-by: Ian Clelland <iclelland@chromium.org>
Reviewed-by: Rick Byers <rbyers@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Reviewed-by: Jason Chase <chasej@chromium.org>
Cr-Commit-Position: refs/heads/master@{#486964}
[modify] https://crrev.com/640aa39844d3f15f8d274f7d9b13a6175d1f1c38/content/browser/renderer_host/render_process_host_impl.cc
[modify] https://crrev.com/640aa39844d3f15f8d274f7d9b13a6175d1f1c38/content/child/runtime_features.cc
[modify] https://crrev.com/640aa39844d3f15f8d274f7d9b13a6175d1f1c38/content/public/common/content_switches.cc
[modify] https://crrev.com/640aa39844d3f15f8d274f7d9b13a6175d1f1c38/content/public/common/content_switches.h
[modify] https://crrev.com/640aa39844d3f15f8d274f7d9b13a6175d1f1c38/third_party/WebKit/LayoutTests/VirtualTestSuites
[modify] https://crrev.com/640aa39844d3f15f8d274f7d9b13a6175d1f1c38/third_party/WebKit/Source/platform/exported/WebRuntimeFeatures.cpp
[modify] https://crrev.com/640aa39844d3f15f8d274f7d9b13a6175d1f1c38/third_party/WebKit/public/platform/WebRuntimeFeatures.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a94fcfb2cbb571f1fe9367a800e538906a31523f

commit a94fcfb2cbb571f1fe9367a800e538906a31523f
Author: Ian Clelland <iclelland@google.com>
Date: Thu Jul 20 03:43:48 2017

Update Origin Trials integration docs.

Two changes have landed recently which need to be reflected in
documentation for origin trials:

- Trials are disabled automatically in the virtual test suite, and do
    not have to be named explicitly in VirtualTestSuites.
- V8 bindings code is now generated automatically

This documentation change brings the developer docs up to date with reality.

BUG= 685788 ,  615060 

Change-Id: Icec69074b654bc749d790136de4e3a72855e3660
Reviewed-on: https://chromium-review.googlesource.com/578171
Reviewed-by: Jason Chase <chasej@chromium.org>
Commit-Queue: Ian Clelland <iclelland@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488127}
[modify] https://crrev.com/a94fcfb2cbb571f1fe9367a800e538906a31523f/docs/origin_trials_integration.md