Track packages to preload in Atom class

src/atom.coffee

@@ -250,6 +250,13 @@ class Atom extends Model
   storeWindowDimensions: ->
     @state.windowDimensions = @getWindowDimensions()
 
+  storeGrammarsForOpenEditors: ->
+    packageNames = []
+    for editor in @workspace.getEditors()
+      {packageName} = editor.getGrammar()
+      packageNames.push(packageName) if packageName
+    @state.packagesWithActiveGrammars = _.uniq(packageNames)
+
   # Public: Get the load settings for the current window.
   #
   # Returns an object containing all the load setting key/value pairs.
@@ -272,6 +279,11 @@ class Atom extends Model
     @packages.packageStates = @state.packageStates ? {}
     delete @state.packageStates
 
+  preloadGrammarsForOpenEditors: ->
+    packagesWithActiveGrammars = @state.packagesWithActiveGrammars ? []
+    for packageName in packagesWithActiveGrammars
+      @packages.getLoadedPackage(packageName)?.loadGrammarsSync()
+
   deserializeEditorWindow: ->
     @deserializePackageStates()
     @deserializeProject()
@@ -293,6 +305,7 @@ class Atom extends Model
     @keymaps.loadBundledKeymaps()
     @themes.loadBaseStylesheets()
     @packages.loadPackages()
+    @preloadGrammarsForOpenEditors()
     @deserializeEditorWindow()
     @packages.activate()
     @keymaps.loadUserKeymap()

src/tokenized-buffer.coffee

@@ -47,18 +47,8 @@ class TokenizedBuffer extends Model
     @reloadGrammar()
 
   serializeParams: ->
-    packageNameForScope = (scope) ->
-      atom.packages.getPackageForGrammarScopeName(scopeName)?.name
-
-    scopeName = @grammar.scopeName
-    packageName = packageNameForScope(@grammar.scopeName)
-    grammars = [{scopeName, packageName}]
-    for scopeName in @grammar.includedGrammarScopes
-      grammars.push {scopeName, packageName: packageNameForScope(scopeName)}
-
     bufferPath: @buffer.getPath()
     tabLength: @tabLength
-    grammars: grammars
 
   deserializeParams: (params) ->
     if params.grammars?

src/window-event-handler.coffee

@@ -42,6 +42,7 @@ class WindowEventHandler
 
     @subscribe $(window), 'unload', ->
       atom.storeWindowDimensions()
+      atom.storeGrammarsForOpenEditors()
 
     @subscribeToCommand $(window), 'window:toggle-full-screen', -> atom.toggleFullScreen()