fix(infiniteGrid): remove unnecessary layout call on resize

if width is not changed, layout should be not called on resize event.

ref o-273, o-282

src/infiniteGrid.js

@@ -180,7 +180,7 @@ eg.module("infiniteGrid", ["jQuery", eg, window, document], function($, ns, glob
 			var self = this;
 			this._resizeTimeout = setTimeout(function() {
 				self._refreshViewport();
-				self.layout(self.items, true);
+				(self.$el.innerWidth() !== self._containerWidth) && self.layout(self.items, true);
 				self._resizeTimeout = null;
 			}, 100);
 		},

test/unit/js/infiniteGrid.test.js

@@ -789,4 +789,32 @@ QUnit.test("check a clear after scrolling", function(assert) {
 			done();
 		}, 100);
 	});
+});
+
+QUnit.test("if width is not changed, layout should be not called on resize event.", function(assert) {
+	// Given
+	var done = assert.async();
+	var resizeCount = 0;
+	var layoutCount = 0;
+	var $global = $(window);
+	var inst = this.inst = new eg.InfiniteGrid("#grid");
+	this.inst.on("layoutComplete", function(e) {
+		this.off("layoutComplete");
+		this.on("layoutComplete", function(e) {
+			assert.ok(false, "layoutComplete event should not be called");
+		});
+	});
+	$global.on("resize", function(e) {
+		resizeCount++;
+	});
+
+	// When
+	$global.trigger("resize");
+
+	// Then
+	setTimeout(function() {
+		assert.ok(resizeCount > 0, "should exist resize event");
+		assert.equal(inst.$el.innerWidth(), inst._containerWidth, "width is not changed");
+		done();
+	},100);
 });