Allow spec window to store window state

It just stores window dimensions for now.

src/app/atom.coffee

@@ -218,20 +218,21 @@ window.atom =
         rootView?.open(path)
 
   getWindowStatePath: ->
-    shasum = crypto.createHash('sha1')
-    shasum.update(@getPathToOpen())
-    fsUtils.join(config.userStoragePath, shasum.digest('hex'))
+    if not @getPathToOpen()
+      'probably-a-spec-window'
+    else
+      shasum = crypto.createHash('sha1')
+      shasum.update(@getPathToOpen())
+      fsUtils.join(config.userStoragePath, shasum.digest('hex'))
 
   setWindowState: (keyPath, value) ->
-    return {} if not @getPathToOpen()
-
     windowState = @getWindowState()
     _.setValueForKeyPath(windowState, keyPath, value)
     fsUtils.write(@getWindowStatePath(), JSON.stringify(windowState))
     windowState
 
   getWindowState: (keyPath) ->
-    return {} if not @getPathToOpen() or not fsUtils.exists(@getWindowStatePath())
+    return {} unless fsUtils.exists(@getWindowStatePath())
 
     windowState = JSON.parse(fsUtils.read(@getWindowStatePath()) or '{}')
     if keyPath

src/app/window.coffee

@@ -40,6 +40,7 @@ window.setUpEnvironment = ->
   dimensions = defaultWindowDimensions unless dimensions.width and dimensions.height
   window.setDimensions(dimensions)
   remote.getCurrentWindow().show()
+  $(window).on 'unload', -> atom.setWindowState('dimensions', window.getDimensions())
 
 # This method is only called when opening a real application window
 window.startEditorWindow = ->
@@ -78,7 +79,6 @@ window.unloadEditorWindow = ->
   atom.setWindowState('project', project.serialize())
   atom.setWindowState('syntax', syntax.serialize())
   atom.setWindowState('rootView', rootView.serialize())
-  atom.setWindowState('dimensions', window.getDimensions())
   atom.deactivatePackages()
   atom.setWindowState('packageStates', atom.packageStates)
   rootView.remove()