Make legend appearance consistent with chart elements (#5621)

src/elements/element.arc.js

@@ -92,6 +92,8 @@ function drawBorder(ctx, vm, arc) {
 }
 
 module.exports = Element.extend({
+	_type: 'arc',
+
 	inLabelRange: function(mouseX) {
 		var vm = this._view;
 

src/elements/element.line.js

@@ -26,6 +26,8 @@ defaults._set('global', {
 });
 
 module.exports = Element.extend({
+	_type: 'line',
+
 	draw: function() {
 		var me = this;
 		var vm = me._view;

src/elements/element.point.js

@@ -35,6 +35,8 @@ function yRange(mouseY) {
 }
 
 module.exports = Element.extend({
+	_type: 'point',
+
 	inRange: function(mouseX, mouseY) {
 		var vm = this._view;
 		return vm ? ((Math.pow(mouseX - vm.x, 2) + Math.pow(mouseY - vm.y, 2)) < Math.pow(vm.hitRadius + vm.radius, 2)) : false;

src/elements/element.rectangle.js

@@ -131,6 +131,8 @@ function inRange(vm, x, y) {
 }
 
 module.exports = Element.extend({
+	_type: 'rectangle',
+
 	draw: function() {
 		var ctx = this._chart.ctx;
 		var vm = this._view;