Cleanup virtual test suites for origin trials

docs/origin_trials_integration.md

Index: docs/origin_trials_integration.md
diff --git a/docs/origin_trials_integration.md b/docs/origin_trials_integration.md
index 227bd6d42727ef44e3b0e84d8b9ed0830d170f30..d56431a8fb07e1c1bc4abb8c9b97d840ac77dc5d 100644
--- a/docs/origin_trials_integration.md
+++ b/docs/origin_trials_integration.md
@@ -153,6 +153,19 @@ it doesn't work, see [trial_token_unittest.cc]. If you cannot set command-line
 switches (e.g., on Chrome OS), you can also directly modify
 [chrome_origin_trial_policy.cc].
 
+### Layout Tests
+When using the \[OriginTrialEnabled\] IDL attribute, you should add layout tests
+to verify that you've correctly updated the V8 bindings code. Depending on how
+your feature is exposed, you'll want tests for the exposed interfaces, as well
+as tests for script-added tokens. For examples, refer to the existing tests in
+[origin_trials/webexposed].
+
+In addition, you'll need to update the command line for the
+`origin-trials-runtimeflags-disabled` virtual suite, in [VirtualTestSuites].
+Add your feature name to the list of explicitly disabled features. This test
+suite ensures that features are actually enabled by origin trial, not overridden
+by the runtime flag.
+
 [build_config.h]: /build/build_config.h
 [chrome_origin_trial_policy.cc]: /chrome/common/origin_trials/chrome_origin_trial_policy.cc
 [crbug.com/615060]: https://bugs.chromium.org/p/chromium/issues/detail?id=615060
@@ -161,5 +174,7 @@ switches (e.g., on Chrome OS), you can also directly modify
 [generate_token.py]: /tools/origin_trials/generate_token.py
 [Developer Guide]: https://github.com/jpchase/OriginTrials/blob/gh-pages/developer-guide.md
 [OriginTrialEnabled]: /third_party/WebKit/Source/bindings/IDLExtendedAttributes.md#_OriginTrialEnabled_i_m_a_c_
+[origin_trials/webexposed]: /third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/
 [RuntimeEnabledFeatures.json5]: /third_party/WebKit/Source/platform/RuntimeEnabledFeatures.json5
 [trial_token_unittest.cc]: /content/common/origin_trials/trial_token_unittest.cc
+[VirtualTestSuites]: /third_party/WebKit/LayoutTests/VirtualTestSuites