This is a rollup of all the patches that have landed on the cedar project branch:
891252fdd0
Bug 1492475 - Part 1: Migrate most, if not all nsSearchService consumers to use async APIs. r=florian
79b2eb2367
Bug 1492475 - Part 2: Move nsIBrowserSearchService.idl to toolkit/components/search/nsISearchService.idl and update references. r=florian
a947d3cdf0
Bug 1492475 - Part 3: The search service init() method should simply return a Promise. r=florian
c1e172dfac
Bug 1492475 - Part 4: Remove the synchronous initialization flow. r=florian
cd41189eac
Bug 1492475 - Part 5: Since async initialization of the search service now is implicit behavior, remove the distinctive verbiage used internally. r=florian
2ae7189dfa
Bug 1492475 - Part 6: Update the cache build task to work with an actual Promise and re-initialize only once at the same time - all to fix race conditions here. r=florian
c8ee92973f
Bug 1492475 - Part 7: Make the region fetch not block the init flow, to ensure it's as fast as possible. r=florian
c44e674e16
Bug 1492475 - Part 8: Introduce an init flag, which can only be used privately, that allows to explicitly skip waiting for the region check process to complete. r=florian
6c79eaf1d3
Bug 1492475 - Part 9: Update unit tests to stop using 'currentEngine', in favor of 'defaultEngine'. r=Standard8
21b3aa17ee
Bug 1492475 - Part 10: Update unit tests to be fully aware of the new, async signatures of the search service API and remove sync init flow tests. r=mkaply,florian
ce5ba69019
Bug 1492475 - Part 11: Repair incorrect usage of the `identifier` property of nsISearchEngine instances. r=florian
fd177a7994
Bug 1518543 - Fix up the Android (Fennec) nsISearchService shim to work with the new asynchronous API. r=florian
3653d8ee22
Bug 1523708 - Change the search service interaction in the show-heartbeat action to use the new async API. r=florian
Differential Revision: https://phabricator.services.mozilla.com/D18355
