commit 5dd9513f5c3838274dc7a5aa91cc163302883228
author Hiroshige Hayashizaki <hiroshige@chromium.org> Wed Mar 06 21:46:50 2019
committer Commit Bot <commit-bot@chromium.org> Wed Mar 06 21:46:50 2019
tree d0a590761c8c8d6be16c71247624804ea4a34204
parent 999fbba8c74b7b9ab3518194d5a63a71f4b79af9

[Layered API] Implement origin trials: BuiltInModuleKvStorage

This CL adds origin_trial_feature_name to
- "BuiltInModuleInfra"
- "BuiltInModuleKvStorage"
While "BuiltInModuleInfra" origin trial is not needed for
end users, this is needed in terms of implementation, because
"BuiltInModuleInfra" should be enabled if "BuiltInModuleKvStorage"
is enabled, and thus "BuiltInModuleInfra" flag should also depend
on origin trials.
By adding origin_trial_feature_name to "BuiltInModuleInfra",
origin_trials::BuiltInModuleInfraEnabled() takes care of
the dependency.

As origin trials requires ExecutionContext, this CL associates
built-in module feature control with Modulator, by introducing
- Modulator::BuiltInModuleInfraEnabled()
- Modulator::BuiltInModuleEnabled()
This CL plumbs Modulator via ModuleScriptFetcher::Fetch() and
ImportMap, to plumb Modulator::BuiltInModule*Enabled() to
layered_api.cc.

It seems a little confusing that ModuleScriptFetcher takes
both Modulator and ResourceFetcher that refer
module map settings object and fetch client settings object,
respectively.
This is actually consistent, because built-in modules are
associated with module map settings object and the current
implementation of import maps is also associated with
Modulator (crbug/928435), while fetching should refer to
fetch client settings object.
This apparent inconsistency should be resolved by
- Fixing Issue 928435, or
- Enabling Built-in modules by default (which will remove
  dependencies to ExecutionContext/Modulator again), or
- Refactoring ModuleScriptFetcher.

This CL implements individual control over built-in modules
in ModulatorImplBase::BuiltInModuleEnabled().
After this CL,
- "BuiltInModuleKvStorage" enables "kv-storage" and "blank" only, and
- "BuiltInModuleInfra" flag enables "blank" only,
while they enabled all built-in modules before this CL.

Bug: 829084, 928435
Change-Id: I0ee2838c0981192e9a993cb784bc39d866682836
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1497468
Commit-Queue: Hiroshige Hayashizaki <hiroshige@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638289}