diff --git a/src/ol/feature.js b/src/ol/feature.js
index 1335ca733e..fdd0e196a8 100644
--- a/src/ol/feature.js
+++ b/src/ol/feature.js
@@ -41,12 +41,6 @@ ol.Feature = function(opt_geometryOrValues) {
    */
   this.geometryName_ = 'geometry';
 
-  /**
-   * @private
-   * @type {number}
-   */
-  this.revision_ = 0;
-
   /**
    * @private
    * @type {goog.events.Key}
@@ -76,15 +70,6 @@ ol.Feature = function(opt_geometryOrValues) {
 goog.inherits(ol.Feature, ol.Object);
 
 
-/**
- * FIXME empty description for jsdoc
- */
-ol.Feature.prototype.dispatchChangeEvent = function() {
-  ++this.revision_;
-  this.dispatchEvent(goog.events.EventType.CHANGE);
-};
-
-
 /**
  * @return {ol.geom.Geometry|undefined} Geometry.
  */
@@ -114,14 +99,6 @@ ol.Feature.prototype.getGeometryName = function() {
 };
 
 
-/**
- * @return {number} Revision.
- */
-ol.Feature.prototype.getRevision = function() {
-  return this.revision_;
-};
-
-
 /**
  * @return {ol.feature.FeatureStyleFunction|undefined} Style function.
  */
diff --git a/src/ol/geom/circle.js b/src/ol/geom/circle.js
index fffb4399c0..b669dee7d6 100644
--- a/src/ol/geom/circle.js
+++ b/src/ol/geom/circle.js
@@ -88,14 +88,14 @@ ol.geom.Circle.prototype.getCenter = function() {
  * @inheritDoc
  */
 ol.geom.Circle.prototype.getExtent = function(opt_extent) {
-  if (this.extentRevision != this.revision) {
+  if (this.extentRevision != this.getRevision()) {
     var flatCoordinates = this.flatCoordinates;
     var radius = flatCoordinates[this.stride] - flatCoordinates[0];
     this.extent = ol.extent.createOrUpdate(
         flatCoordinates[0] - radius, flatCoordinates[1] - radius,
         flatCoordinates[0] + radius, flatCoordinates[1] + radius,
         this.extent);
-    this.extentRevision = this.revision;
+    this.extentRevision = this.getRevision();
   }
   goog.asserts.assert(goog.isDef(this.extent));
   return ol.extent.returnOrUpdate(this.extent, opt_extent);
diff --git a/src/ol/geom/geometry.js b/src/ol/geom/geometry.js
index 7a41e08503..1907b580bc 100644
--- a/src/ol/geom/geometry.js
+++ b/src/ol/geom/geometry.js
@@ -2,7 +2,6 @@ goog.provide('ol.geom.Geometry');
 goog.provide('ol.geom.GeometryType');
 
 goog.require('goog.asserts');
-goog.require('goog.events.EventType');
 goog.require('goog.functions');
 goog.require('ol.Observable');
 
@@ -43,12 +42,6 @@ ol.geom.Geometry = function() {
 
   goog.base(this);
 
-  /**
-   * @protected
-   * @type {number}
-   */
-  this.revision = 0;
-
   /**
    * @protected
    * @type {ol.Extent|undefined}
@@ -129,15 +122,6 @@ ol.geom.Geometry.prototype.containsCoordinate = function(coordinate) {
 ol.geom.Geometry.prototype.containsXY = goog.functions.FALSE;
 
 
-/**
- * FIXME empty description for jsdoc
- */
-ol.geom.Geometry.prototype.dispatchChangeEvent = function() {
-  ++this.revision;
-  this.dispatchEvent(goog.events.EventType.CHANGE);
-};
-
-
 /**
  * @param {ol.Extent=} opt_extent Extent.
  * @return {ol.Extent} extent Extent.
@@ -145,14 +129,6 @@ ol.geom.Geometry.prototype.dispatchChangeEvent = function() {
 ol.geom.Geometry.prototype.getExtent = goog.abstractMethod;
 
 
-/**
- * @return {number} Revision.
- */
-ol.geom.Geometry.prototype.getRevision = function() {
-  return this.revision;
-};
-
-
 /**
  * @param {number} squaredTolerance Squared tolerance.
  * @return {ol.geom.Geometry} Simplified geometry.
diff --git a/src/ol/geom/geometrycollection.js b/src/ol/geom/geometrycollection.js
index e37e0dd04d..1c4f3cbfe2 100644
--- a/src/ol/geom/geometrycollection.js
+++ b/src/ol/geom/geometrycollection.js
@@ -91,7 +91,7 @@ ol.geom.GeometryCollection.prototype.containsXY = function(x, y) {
  * @inheritDoc
  */
 ol.geom.GeometryCollection.prototype.getExtent = function(opt_extent) {
-  if (this.extentRevision != this.revision) {
+  if (this.extentRevision != this.getRevision()) {
     var extent = ol.extent.createOrUpdateEmpty(this.extent);
     var geometries = this.geometries_;
     var i, ii;
@@ -99,7 +99,7 @@ ol.geom.GeometryCollection.prototype.getExtent = function(opt_extent) {
       ol.extent.extend(extent, geometries[i].getExtent());
     }
     this.extent = extent;
-    this.extentRevision = this.revision;
+    this.extentRevision = this.getRevision();
   }
   goog.asserts.assert(goog.isDef(this.extent));
   return ol.extent.returnOrUpdate(this.extent, opt_extent);
@@ -127,10 +127,10 @@ ol.geom.GeometryCollection.prototype.getGeometriesArray = function() {
  */
 ol.geom.GeometryCollection.prototype.getSimplifiedGeometry =
     function(squaredTolerance) {
-  if (this.simplifiedGeometryRevision != this.revision) {
+  if (this.simplifiedGeometryRevision != this.getRevision()) {
     goog.object.clear(this.simplifiedGeometryCache);
     this.simplifiedGeometryMaxMinSquaredTolerance = 0;
-    this.simplifiedGeometryRevision = this.revision;
+    this.simplifiedGeometryRevision = this.getRevision();
   }
   if (squaredTolerance < 0 ||
       (this.simplifiedGeometryMaxMinSquaredTolerance !== 0 &&
diff --git a/src/ol/geom/linearring.js b/src/ol/geom/linearring.js
index 1772b5f0ab..c74a20bb59 100644
--- a/src/ol/geom/linearring.js
+++ b/src/ol/geom/linearring.js
@@ -56,10 +56,10 @@ ol.geom.LinearRing.prototype.closestPointXY =
       ol.extent.closestSquaredDistanceXY(this.getExtent(), x, y)) {
     return minSquaredDistance;
   }
-  if (this.maxDeltaRevision_ != this.revision) {
+  if (this.maxDeltaRevision_ != this.getRevision()) {
     this.maxDelta_ = Math.sqrt(ol.geom.closest.getMaxSquaredDelta(
         this.flatCoordinates, 0, this.flatCoordinates.length, this.stride, 0));
-    this.maxDeltaRevision_ = this.revision;
+    this.maxDeltaRevision_ = this.getRevision();
   }
   return ol.geom.closest.getClosestPoint(
       this.flatCoordinates, 0, this.flatCoordinates.length, this.stride,
diff --git a/src/ol/geom/linestring.js b/src/ol/geom/linestring.js
index acc3ac8053..3f94e05a72 100644
--- a/src/ol/geom/linestring.js
+++ b/src/ol/geom/linestring.js
@@ -56,10 +56,10 @@ ol.geom.LineString.prototype.closestPointXY =
       ol.extent.closestSquaredDistanceXY(this.getExtent(), x, y)) {
     return minSquaredDistance;
   }
-  if (this.maxDeltaRevision_ != this.revision) {
+  if (this.maxDeltaRevision_ != this.getRevision()) {
     this.maxDelta_ = Math.sqrt(ol.geom.closest.getMaxSquaredDelta(
         this.flatCoordinates, 0, this.flatCoordinates.length, this.stride, 0));
-    this.maxDeltaRevision_ = this.revision;
+    this.maxDeltaRevision_ = this.getRevision();
   }
   return ol.geom.closest.getClosestPoint(
       this.flatCoordinates, 0, this.flatCoordinates.length, this.stride,
diff --git a/src/ol/geom/multilinestring.js b/src/ol/geom/multilinestring.js
index c649e41a52..76256ca336 100644
--- a/src/ol/geom/multilinestring.js
+++ b/src/ol/geom/multilinestring.js
@@ -66,10 +66,10 @@ ol.geom.MultiLineString.prototype.closestPointXY =
       ol.extent.closestSquaredDistanceXY(this.getExtent(), x, y)) {
     return minSquaredDistance;
   }
-  if (this.maxDeltaRevision_ != this.revision) {
+  if (this.maxDeltaRevision_ != this.getRevision()) {
     this.maxDelta_ = Math.sqrt(ol.geom.closest.getsMaxSquaredDelta(
         this.flatCoordinates, 0, this.ends_, this.stride, 0));
-    this.maxDeltaRevision_ = this.revision;
+    this.maxDeltaRevision_ = this.getRevision();
   }
   return ol.geom.closest.getsClosestPoint(
       this.flatCoordinates, 0, this.ends_, this.stride,
diff --git a/src/ol/geom/multipolygon.js b/src/ol/geom/multipolygon.js
index 27727e70a4..2f3e25966f 100644
--- a/src/ol/geom/multipolygon.js
+++ b/src/ol/geom/multipolygon.js
@@ -76,10 +76,10 @@ ol.geom.MultiPolygon.prototype.closestPointXY =
       ol.extent.closestSquaredDistanceXY(this.getExtent(), x, y)) {
     return minSquaredDistance;
   }
-  if (this.maxDeltaRevision_ != this.revision) {
+  if (this.maxDeltaRevision_ != this.getRevision()) {
     this.maxDelta_ = Math.sqrt(ol.geom.closest.getssMaxSquaredDelta(
         this.flatCoordinates, 0, this.endss_, this.stride, 0));
-    this.maxDeltaRevision_ = this.revision;
+    this.maxDeltaRevision_ = this.getRevision();
   }
   return ol.geom.closest.getssClosestPoint(
       this.flatCoordinates, 0, this.endss_, this.stride,
@@ -126,12 +126,12 @@ ol.geom.MultiPolygon.prototype.getEndss = function() {
  * @return {Array.<ol.Coordinate>} Interior points.
  */
 ol.geom.MultiPolygon.prototype.getInteriorPoints = function() {
-  if (this.interiorPointsRevision_ != this.revision) {
+  if (this.interiorPointsRevision_ != this.getRevision()) {
     var ys = ol.geom.flat.linearRingssMidYs(
         this.flatCoordinates, 0, this.endss_, this.stride);
     this.interiorPoints_ = ol.geom.flat.linearRingssGetInteriorPoints(
         this.flatCoordinates, 0, this.endss_, this.stride, ys);
-    this.interiorPointsRevision_ = this.revision;
+    this.interiorPointsRevision_ = this.getRevision();
   }
   return this.interiorPoints_;
 };
diff --git a/src/ol/geom/point.js b/src/ol/geom/point.js
index 46c76b5a9a..540048ef07 100644
--- a/src/ol/geom/point.js
+++ b/src/ol/geom/point.js
@@ -65,10 +65,10 @@ ol.geom.Point.prototype.getCoordinates = function() {
  * @inheritDoc
  */
 ol.geom.Point.prototype.getExtent = function(opt_extent) {
-  if (this.extentRevision != this.revision) {
+  if (this.extentRevision != this.getRevision()) {
     this.extent = ol.extent.createOrUpdateFromCoordinate(
         this.flatCoordinates, this.extent);
-    this.extentRevision = this.revision;
+    this.extentRevision = this.getRevision();
   }
   goog.asserts.assert(goog.isDef(this.extent));
   return ol.extent.returnOrUpdate(this.extent, opt_extent);
diff --git a/src/ol/geom/polygon.js b/src/ol/geom/polygon.js
index 50b2f276e4..3b1cb59981 100644
--- a/src/ol/geom/polygon.js
+++ b/src/ol/geom/polygon.js
@@ -76,10 +76,10 @@ ol.geom.Polygon.prototype.closestPointXY =
       ol.extent.closestSquaredDistanceXY(this.getExtent(), x, y)) {
     return minSquaredDistance;
   }
-  if (this.maxDeltaRevision_ != this.revision) {
+  if (this.maxDeltaRevision_ != this.getRevision()) {
     this.maxDelta_ = Math.sqrt(ol.geom.closest.getsMaxSquaredDelta(
         this.flatCoordinates, 0, this.ends_, this.stride, 0));
-    this.maxDeltaRevision_ = this.revision;
+    this.maxDeltaRevision_ = this.getRevision();
   }
   return ol.geom.closest.getsClosestPoint(
       this.flatCoordinates, 0, this.ends_, this.stride,
@@ -126,12 +126,12 @@ ol.geom.Polygon.prototype.getEnds = function() {
  * @return {ol.Coordinate} Interior point.
  */
 ol.geom.Polygon.prototype.getInteriorPoint = function() {
-  if (this.interiorPointRevision_ != this.revision) {
+  if (this.interiorPointRevision_ != this.getRevision()) {
     var extent = this.getExtent();
     var y = (extent[1] + extent[3]) / 2;
     this.interiorPoint_ = ol.geom.flat.linearRingsGetInteriorPoint(
         this.flatCoordinates, 0, this.ends_, this.stride, y);
-    this.interiorPointRevision_ = this.revision;
+    this.interiorPointRevision_ = this.getRevision();
   }
   return this.interiorPoint_;
 };
diff --git a/src/ol/geom/simplegeometry.js b/src/ol/geom/simplegeometry.js
index 2f24d9d28f..26420ab3fd 100644
--- a/src/ol/geom/simplegeometry.js
+++ b/src/ol/geom/simplegeometry.js
@@ -87,10 +87,10 @@ ol.geom.SimpleGeometry.prototype.containsXY = goog.functions.FALSE;
  * @inheritDoc
  */
 ol.geom.SimpleGeometry.prototype.getExtent = function(opt_extent) {
-  if (this.extentRevision != this.revision) {
+  if (this.extentRevision != this.getRevision()) {
     this.extent = ol.extent.createOrUpdateFromFlatCoordinates(
         this.flatCoordinates, this.stride, this.extent);
-    this.extentRevision = this.revision;
+    this.extentRevision = this.getRevision();
   }
   goog.asserts.assert(goog.isDef(this.extent));
   return ol.extent.returnOrUpdate(this.extent, opt_extent);
@@ -118,10 +118,10 @@ ol.geom.SimpleGeometry.prototype.getLayout = function() {
  */
 ol.geom.SimpleGeometry.prototype.getSimplifiedGeometry =
     function(squaredTolerance) {
-  if (this.simplifiedGeometryRevision != this.revision) {
+  if (this.simplifiedGeometryRevision != this.getRevision()) {
     goog.object.clear(this.simplifiedGeometryCache);
     this.simplifiedGeometryMaxMinSquaredTolerance = 0;
-    this.simplifiedGeometryRevision = this.revision;
+    this.simplifiedGeometryRevision = this.getRevision();
   }
   // If squaredTolerance is negative or if we know that simplification will not
   // have any effect then just return this.
diff --git a/src/ol/layer/layerbase.js b/src/ol/layer/layerbase.js
index 8ddeeb3c32..46bc1b7d2c 100644
--- a/src/ol/layer/layerbase.js
+++ b/src/ol/layer/layerbase.js
@@ -3,7 +3,6 @@ goog.provide('ol.layer.LayerProperty');
 goog.provide('ol.layer.LayerState');
 
 goog.require('goog.events');
-goog.require('goog.events.EventType');
 goog.require('goog.math');
 goog.require('goog.object');
 goog.require('ol.Object');
@@ -75,14 +74,6 @@ ol.layer.Base = function(options) {
 goog.inherits(ol.layer.Base, ol.Object);
 
 
-/**
- * @protected
- */
-ol.layer.Base.prototype.dispatchChangeEvent = function() {
-  this.dispatchEvent(goog.events.EventType.CHANGE);
-};
-
-
 /**
  * @return {number|undefined} Brightness.
  */
diff --git a/src/ol/observable.js b/src/ol/observable.js
index c3d51b1d24..f48e3a6599 100644
--- a/src/ol/observable.js
+++ b/src/ol/observable.js
@@ -2,6 +2,7 @@ goog.provide('ol.Observable');
 
 goog.require('goog.events');
 goog.require('goog.events.EventTarget');
+goog.require('goog.events.EventType');
 
 
 
@@ -15,12 +16,36 @@ goog.require('goog.events.EventTarget');
  * @todo stability experimental
  */
 ol.Observable = function() {
+
   goog.base(this);
 
+  /**
+   * @private
+   * @type {number}
+   */
+  this.revision_ = 0;
+
 };
 goog.inherits(ol.Observable, goog.events.EventTarget);
 
 
+/**
+ * FIXME empty description for jsdoc
+ */
+ol.Observable.prototype.dispatchChangeEvent = function() {
+  ++this.revision_;
+  this.dispatchEvent(goog.events.EventType.CHANGE);
+};
+
+
+/**
+ * @return {number} Revision.
+ */
+ol.Observable.prototype.getRevision = function() {
+  return this.revision_;
+};
+
+
 /**
  * Listen for a certain type of event.
  * @param {string|Array.<string>} type The event type or array of event types.
diff --git a/src/ol/source/source.js b/src/ol/source/source.js
index d07f916bdb..03f0fa027e 100644
--- a/src/ol/source/source.js
+++ b/src/ol/source/source.js
@@ -74,25 +74,10 @@ ol.source.Source = function(options) {
   this.state_ = goog.isDef(options.state) ?
       options.state : ol.source.State.READY;
 
-  /**
-   * @private
-   * @type {number}
-   */
-  this.revision_ = 0;
-
 };
 goog.inherits(ol.source.Source, ol.Observable);
 
 
-/**
- * @protected
- */
-ol.source.Source.prototype.dispatchChangeEvent = function() {
-  ++this.revision_;
-  this.dispatchEvent(goog.events.EventType.CHANGE);
-};
-
-
 /**
  * @param {ol.Extent} extent Extent.
  * @param {number} resolution Resolution.
@@ -144,14 +129,6 @@ ol.source.Source.prototype.getProjection = function() {
 ol.source.Source.prototype.getResolutions = goog.abstractMethod;
 
 
-/**
- * @return {number} Revision.
- */
-ol.source.Source.prototype.getRevision = function() {
-  return this.revision_;
-};
-
-
 /**
  * @return {ol.source.State} State.
  */