Use an abstract base class instead of IVectorContext

By having the abstract methods in the base class, subclasses can simply
override the methods they actually provide.
Additionally, this change fixes a regression in webgl canvas immediate.

src/ol/render/webgl/webglreplay.js

@@ -9,7 +9,7 @@ goog.require('goog.vec.Mat4');
 goog.require('ol.color.Matrix');
 goog.require('ol.extent');
 goog.require('ol.render.IReplayGroup');
-goog.require('ol.render.IVectorContext');
+goog.require('ol.render.VectorContext');
 goog.require('ol.render.webgl.imagereplay.shader.Color');
 goog.require('ol.render.webgl.imagereplay.shader.Default');
 goog.require('ol.vec.Mat4');
@@ -20,13 +20,14 @@ goog.require('ol.webgl.Context');
 
 /**
  * @constructor
- * @implements {ol.render.IVectorContext}
+ * @extends {ol.render.VectorContext}
  * @param {number} tolerance Tolerance.
  * @param {ol.Extent} maxExtent Max extent.
  * @protected
  * @struct
  */
 ol.render.webgl.ImageReplay = function(tolerance, maxExtent) {
+  goog.base(this);
 
   /**
    * @type {number|undefined}
@@ -219,8 +220,8 @@ ol.render.webgl.ImageReplay = function(tolerance, maxExtent) {
    * @private
    */
   this.width_ = undefined;
-
 };
+goog.inherits(ol.render.webgl.ImageReplay, ol.render.VectorContext);
 
 
 /**
@@ -380,39 +381,6 @@ ol.render.webgl.ImageReplay.prototype.drawCoordinates_ =
 };
 
 
-/**
- * @inheritDoc
- */
-ol.render.webgl.ImageReplay.prototype.drawCircleGeometry = goog.abstractMethod;
-
-
-/**
- * @inheritDoc
- */
-ol.render.webgl.ImageReplay.prototype.drawFeature = goog.abstractMethod;
-
-
-/**
- * @inheritDoc
- */
-ol.render.webgl.ImageReplay.prototype.drawGeometryCollectionGeometry =
-    goog.abstractMethod;
-
-
-/**
- * @inheritDoc
- */
-ol.render.webgl.ImageReplay.prototype.drawLineStringGeometry =
-    goog.abstractMethod;
-
-
-/**
- * @inheritDoc
- */
-ol.render.webgl.ImageReplay.prototype.drawMultiLineStringGeometry =
-    goog.abstractMethod;
-
-
 /**
  * @inheritDoc
  */
@@ -427,13 +395,6 @@ ol.render.webgl.ImageReplay.prototype.drawMultiPointGeometry =
 };
 
 
-/**
- * @inheritDoc
- */
-ol.render.webgl.ImageReplay.prototype.drawMultiPolygonGeometry =
-    goog.abstractMethod;
-
-
 /**
  * @inheritDoc
  */
@@ -448,18 +409,6 @@ ol.render.webgl.ImageReplay.prototype.drawPointGeometry =
 };
 
 
-/**
- * @inheritDoc
- */
-ol.render.webgl.ImageReplay.prototype.drawPolygonGeometry = goog.abstractMethod;
-
-
-/**
- * @inheritDoc
- */
-ol.render.webgl.ImageReplay.prototype.drawText = goog.abstractMethod;
-
-
 /**
  * @param {ol.webgl.Context} context Context.
  */
@@ -1003,12 +952,6 @@ ol.render.webgl.ImageReplay.prototype.setImageStyle = function(imageStyle) {
 };
 
 
-/**
- * @inheritDoc
- */
-ol.render.webgl.ImageReplay.prototype.setTextStyle = goog.abstractMethod;
-
-
 
 /**
  * @constructor