Add an event for after the user keymap has loaded.

src/keymap-extensions.coffee

@@ -8,6 +8,9 @@ bundledKeymaps = require('../package.json')?._atomKeymaps
 KeymapManager::onDidLoadBundledKeymaps = (callback) ->
   @emitter.on 'did-load-bundled-keymaps', callback
 
+KeymapManager::onDidLoadUserKeymap = (callback) ->
+  @emitter.on 'did-load-user-keymap', callback
+
 KeymapManager::loadBundledKeymaps = ->
   keymapsPath = path.join(@resourcePath, 'keymaps')
   if bundledKeymaps?
@@ -32,8 +35,10 @@ KeymapManager::loadUserKeymap = ->
   return unless fs.isFileSync(userKeymapPath)
 
   try
+    errorLoading = false
     @loadKeymap(userKeymapPath, watch: true, suppressErrors: true, priority: 100)
   catch error
+    errorLoading = true
     if error.message.indexOf('Unable to watch path') > -1
       message = """
         Unable to watch path: `#{path.basename(userKeymapPath)}`. Make sure you
@@ -49,6 +54,9 @@ KeymapManager::loadUserKeymap = ->
       stack = error.stack
       @notificationManager.addFatalError(error.message, {detail, stack, dismissable: true})
 
+  @emitter.emit 'did-load-user-keymap' unless errorLoading
+
+
 KeymapManager::subscribeToFileReadFailure = ->
   @onDidFailToReadFile (error) =>
     userKeymapPath = @getUserKeymapPath()