1293126 - Schemas.load in content's ExtensionContext should be removed

Status: RESOLVED FIXED

(WebExtensions :: Untriaged, defect)

Description

[Rob Wu [:robwu]]

The use of Schemas.load in ExtensionContent.jsm's ExtensionContext [1] comes with the assumption that the schema can synchronously be loaded. This is only the case if the method is called in the content process *and* if the JSON data is already loaded at the invocation. These dependencies were not explicit but I confirmed that they are true.

Schemas.load was refactored in bug 1263011, and now the schema data is immediately available at the start of the content process.
In the main process, the schema is loaded asynchronously, so the use of Schemas.load as in [1] is of no use for the Schemas.inject call down a few lines.

Note that Schemas.load is useless in the main process, regardless of that patch because of the async loading, and because of the dependency of ExtensionContext on the existence of an extension, which in its turn depends on a loaded extension, which ultimately requires all schemas to be loaded in the main process.

Given that Schemas.load in ExtensionContent.jsm is of no use, I'm going to remove it.

[1] http://searchfox.org/mozilla-central/rev/389a3e0817b873a64376ec2b65f6807afbba9d8f/toolkit/components/extensions/ExtensionContent.jsm#431

Comment 1

[Rob Wu [:robwu]]

Attachment: Bug 1293126 - Remove Schemas.load from content's ExtensionContext

Review commit: https://reviewboard.mozilla.org/r/69878/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/69878/

Comment 2

[Andrew Swan [:aswan]]

Comment on attachment 8778721 [details]
Bug 1293126 - Remove Schemas.load from content's ExtensionContext

https://reviewboard.mozilla.org/r/69878/#review67398

This all seems reasonable to me but Kris knows all the history and context (no pun intended) here much better than I do so I'm going to punt over to him.
Also for something like this a try run before landing seems wise.

Comment 3

[Kris Maglione [:kmag]]

Comment on attachment 8778721 [details]
Bug 1293126 - Remove Schemas.load from content's ExtensionContext

https://reviewboard.mozilla.org/r/69878/#review67410

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/cc089b038c95
Remove Schemas.load from content's ExtensionContext r=kmag

Comment 5

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/cc089b038c95