Fixes issue of Pixi DisplayObject width/height sending an emitter scale into Infinity.

Author: photonstorm

src/particles/arcade/Emitter.js

@@ -719,6 +719,38 @@ Phaser.Particles.Arcade.Emitter.prototype.at = function (object) {
 
 };
 
+/**
+* @name Phaser.Particles.Arcade.Emitter#width
+* @property {number} width - Gets or sets the width of the Emitter. This is the region in which a particle can be emitted.
+*/
+Object.defineProperty(Phaser.Particles.Arcade.Emitter.prototype, "width", {
+
+    get: function () {
+        return this.area.width;
+    },
+
+    set: function (value) {
+        this.area.width = value;
+    }
+
+});
+
+/**
+* @name Phaser.Particles.Arcade.Emitter#height
+* @property {number} height - Gets or sets the height of the Emitter. This is the region in which a particle can be emitted.
+*/
+Object.defineProperty(Phaser.Particles.Arcade.Emitter.prototype, "height", {
+
+    get: function () {
+        return this.area.height;
+    },
+
+    set: function (value) {
+        this.area.height = value;
+    }
+
+});
+
 /**
 * @name Phaser.Particles.Arcade.Emitter#x
 * @property {number} x - Gets or sets the x position of the Emitter.