feat: new makeSingleInstance API (#12782)

* Refactor app.makeSingleInstance
* new API `app.isPrimaryInstance()`
* new API `app.isSingleInstance()`
* new event `app.on('second-instance')`
* deprecated old syntax `app.makeSingleInstance(cb)`
* deprecated old syntax of `app.makeSingleInstance() --> bool` in favor
of `app.isPrimaryInstance()`
* Fix spec, we don't need process.nextTick hacks any more
* Make deprecation TODO for the return value of makeSingleInstance
* Refactor makeSingleInstance to requestSingleInstanceLock and add appropriate deprecation comments
* I swear this isn't tricking the linter
* Make const
* Add deprecation warnings for release, and add to planned-breaking-changes

BREAKING CHANGE

lib/browser/api/app.js

@@ -109,6 +109,21 @@ for (let name of events) {
   })
 }
 
+// TODO(MarshallOfSound): Remove in 4.0
+app.releaseSingleInstance = () => {
+  deprecate.warn('app.releaseSingleInstance(cb)', 'app.releaseSingleInstanceLock()')
+  app.releaseSingleInstanceLock()
+}
+
+// TODO(MarshallOfSound): Remove in 4.0
+app.makeSingleInstance = (oldStyleFn) => {
+  deprecate.warn('app.makeSingleInstance(cb)', 'app.requestSingleInstanceLock() and app.on(\'second-instance\', cb)')
+  if (oldStyleFn && typeof oldStyleFn === 'function') {
+    app.on('second-instance', (event, ...args) => oldStyleFn(...args))
+  }
+  return !app.requestSingleInstanceLock()
+}
+
 // Wrappers for native classes.
 const {DownloadItem} = process.atomBinding('download_item')
 Object.setPrototypeOf(DownloadItem.prototype, EventEmitter.prototype)