Add canvas renderer

src/ol/renderer/canvas/canvaslayerrenderer.js

@@ -0,0 +1,37 @@
+goog.provide('ol.renderer.canvas.Layer');
+
+goog.require('ol.FrameState');
+goog.require('ol.layer.LayerState');
+goog.require('ol.renderer.Layer');
+
+
+
+/**
+ * @constructor
+ * @extends {ol.renderer.Layer}
+ * @param {ol.renderer.Map} mapRenderer Map renderer.
+ * @param {ol.layer.Layer} layer Layer.
+ */
+ol.renderer.canvas.Layer = function(mapRenderer, layer) {
+  goog.base(this, mapRenderer, layer);
+};
+goog.inherits(ol.renderer.canvas.Layer, ol.renderer.Layer);
+
+
+/**
+ * @return {HTMLCanvasElement|HTMLVideoElement|Image} Canvas.
+ */
+ol.renderer.canvas.Layer.prototype.getImage = goog.abstractMethod;
+
+
+/**
+ * @return {!goog.vec.Mat4.Number} Transform.
+ */
+ol.renderer.canvas.Layer.prototype.getTransform = goog.abstractMethod;
+
+
+/**
+ * @param {ol.FrameState} frameState Frame state.
+ * @param {ol.layer.LayerState} layerState Layer state.
+ */
+ol.renderer.canvas.Layer.prototype.renderFrame = goog.abstractMethod;