Use @observable annotation instead of @todo observable

src/ol/control/mousepositioncontrol.js

@@ -129,7 +129,7 @@ ol.control.MousePosition.prototype.handleProjectionChanged_ = function() {
 /**
  * @return {ol.CoordinateFormatType|undefined} The format to render the current
  *     position in.
- * @todo observable
+ * @observable
  * @api
  */
 ol.control.MousePosition.prototype.getCoordinateFormat = function() {
@@ -145,7 +145,7 @@ goog.exportProperty(
 /**
  * @return {ol.proj.Projection|undefined} The projection to report mouse
  *     position in.
- * @todo observable
+ * @observable
  * @api
  */
 ol.control.MousePosition.prototype.getProjection = function() {
@@ -202,7 +202,7 @@ ol.control.MousePosition.prototype.setMap = function(map) {
 /**
  * @param {ol.CoordinateFormatType} format The format to render the current
  *     position in.
- * @todo observable
+ * @observable
  * @api
  */
 ol.control.MousePosition.prototype.setCoordinateFormat = function(format) {
@@ -217,7 +217,7 @@ goog.exportProperty(
 /**
  * @param {ol.proj.Projection} projection The projection to report mouse
  *     position in.
- * @todo observable
+ * @observable
  * @api
  */
 ol.control.MousePosition.prototype.setProjection = function(projection) {

src/ol/control/scalelinecontrol.js

@@ -137,7 +137,7 @@ ol.control.ScaleLine.LEADING_DIGITS = [1, 2, 5];
 /**
  * @return {ol.control.ScaleLineUnits|undefined} The units to use in the scale
  *     line.
- * @todo observable
+ * @observable
  * @api
  */
 ol.control.ScaleLine.prototype.getUnits = function() {
@@ -174,7 +174,7 @@ ol.control.ScaleLine.prototype.handleUnitsChanged_ = function() {
 
 /**
  * @param {ol.control.ScaleLineUnits} units The units to use in the scale line.
- * @todo observable
+ * @observable
  * @api
  */
 ol.control.ScaleLine.prototype.setUnits = function(units) {