Remove unnecessary type cast

src/ol/renderer/canvas/canvasimagelayerrenderer.js

@@ -11,7 +11,6 @@ goog.require('ol.extent');
 goog.require('ol.layer.Image');
 goog.require('ol.renderer.Map');
 goog.require('ol.renderer.canvas.Layer');
-goog.require('ol.source.Image');
 goog.require('ol.vec.Mat4');
 
 
@@ -49,7 +48,6 @@ ol.renderer.canvas.ImageLayer.prototype.forEachFeatureAtPixel =
     function(coordinate, frameState, callback, thisArg) {
   var layer = this.getLayer();
   var source = layer.getSource();
-  goog.asserts.assertInstanceof(source, ol.source.Image);
   var extent = frameState.extent;
   var resolution = frameState.viewState.resolution;
   var rotation = frameState.viewState.rotation;
@@ -99,7 +97,6 @@ ol.renderer.canvas.ImageLayer.prototype.prepareFrame =
   var imageLayer = this.getLayer();
   goog.asserts.assertInstanceof(imageLayer, ol.layer.Image);
   var imageSource = imageLayer.getSource();
-  goog.asserts.assertInstanceof(imageSource, ol.source.Image);
 
   var hints = frameState.viewHints;
 

src/ol/renderer/dom/domimagelayerrenderer.js

@@ -13,7 +13,6 @@ goog.require('ol.dom');
 goog.require('ol.extent');
 goog.require('ol.layer.Image');
 goog.require('ol.renderer.dom.Layer');
-goog.require('ol.source.Image');
 goog.require('ol.vec.Mat4');
 
 
@@ -54,7 +53,6 @@ ol.renderer.dom.ImageLayer.prototype.forEachFeatureAtPixel =
     function(coordinate, frameState, callback, thisArg) {
   var layer = this.getLayer();
   var source = layer.getSource();
-  goog.asserts.assertInstanceof(source, ol.source.Image);
   var extent = frameState.extent;
   var resolution = frameState.viewState.resolution;
   var rotation = frameState.viewState.rotation;
@@ -86,7 +84,6 @@ ol.renderer.dom.ImageLayer.prototype.prepareFrame =
   var imageLayer = this.getLayer();
   goog.asserts.assertInstanceof(imageLayer, ol.layer.Image);
   var imageSource = imageLayer.getSource();
-  goog.asserts.assertInstanceof(imageSource, ol.source.Image);
 
   var hints = frameState.viewHints;
 

src/ol/renderer/webgl/webglimagelayerrenderer.js

@@ -13,7 +13,6 @@ goog.require('ol.ViewHint');
 goog.require('ol.extent');
 goog.require('ol.layer.Image');
 goog.require('ol.renderer.webgl.Layer');
-goog.require('ol.source.Image');
 
 
 
@@ -80,7 +79,6 @@ ol.renderer.webgl.ImageLayer.prototype.forEachFeatureAtPixel =
     function(coordinate, frameState, callback, thisArg) {
   var layer = this.getLayer();
   var source = layer.getSource();
-  goog.asserts.assertInstanceof(source, ol.source.Image);
   var extent = frameState.extent;
   var resolution = frameState.viewState.resolution;
   var rotation = frameState.viewState.rotation;
@@ -116,7 +114,6 @@ ol.renderer.webgl.ImageLayer.prototype.prepareFrame =
   var imageLayer = this.getLayer();
   goog.asserts.assertInstanceof(imageLayer, ol.layer.Image);
   var imageSource = imageLayer.getSource();
-  goog.asserts.assertInstanceof(imageSource, ol.source.Image);
 
   var hints = frameState.viewHints;