Added test

Apps/SampleData/Cesium3DTiles/Tilesets/Tileset/tileset.json

@@ -3,6 +3,7 @@
     "version": "1.0",
     "tilesetVersion": "1.2.3"
   },
+  "extras": { "hey":12 },
   "properties": {
     "id": {
       "minimum": 0,
@@ -61,6 +62,7 @@
           ]
         },
         "geometricError": 0,
+	"extras": { "special": true },
         "content": {
           "uri": "ll.b3dm"
         }

Specs/Data/Cesium3DTiles/Tilesets/TilesetWithExtras/tileset.json

@@ -0,0 +1,124 @@
+{
+  "asset": {
+    "version": "1.0",
+    "tilesetVersion": "1.2.3"
+  },
+  "properties": {
+    "id": {
+      "minimum": 0,
+      "maximum": 9
+    },
+    "Longitude": {
+      "minimum": -1.3197192952275933,
+      "maximum": -1.319644104024109
+    },
+    "Latitude": {
+      "minimum": 0.698848878034009,
+      "maximum": 0.6989046192460953
+    },
+    "Height": {
+      "minimum": 6.161747192963958,
+      "maximum": 85.41026367992163
+    }
+  },
+  "geometricError": 240,
+  "extras": {
+      "key": "value"
+    },
+  "root": {
+    "boundingVolume": {
+      "region": [
+        -1.3197209591796106,
+        0.6988424218,
+        -1.3196390408203893,
+        0.6989055782,
+        0,
+        88
+      ]
+    },
+    "geometricError": 70,
+    "extras": {
+        "key": "value"
+    },
+    "refine": "ADD",
+    "content": {
+      "uri": "parent.b3dm",
+      "boundingVolume": {
+        "region": [
+          -1.3197004795898053,
+          0.6988582109,
+          -1.3196595204101946,
+          0.6988897891,
+          0,
+          88
+        ]
+      }
+    },
+    "children": [
+      {
+        "boundingVolume": {
+          "region": [
+            -1.3197209591796106,
+            0.6988424218,
+            -1.31968,
+            0.698874,
+            0,
+            20
+          ]
+        },
+        "geometricError": 0,
+        "content": {
+          "uri": "ll.b3dm"
+        }
+      },
+      {
+        "boundingVolume": {
+          "region": [
+            -1.31968,
+            0.6988424218,
+            -1.3196390408203893,
+            0.698874,
+            0,
+            20
+          ]
+        },
+        "geometricError": 0,
+        "content": {
+          "uri": "lr.b3dm"
+        }
+      },
+      {
+        "boundingVolume": {
+          "region": [
+            -1.31968,
+            0.698874,
+            -1.3196390408203893,
+            0.6989055782,
+            0,
+            20
+          ]
+        },
+        "geometricError": 0,
+        "content": {
+          "uri": "ur.b3dm"
+        }
+      },
+      {
+        "boundingVolume": {
+          "region": [
+            -1.3197209591796106,
+            0.698874,
+            -1.31968,
+            0.6989055782,
+            0,
+            20
+          ]
+        },
+        "geometricError": 0,
+        "content": {
+          "uri": "ul.b3dm"
+        }
+      }
+    ]
+  }
+}

Specs/Scene/Cesium3DTilesetSpec.js

@@ -132,6 +132,8 @@ defineSuite([
     var pointCloudUrl = 'Data/Cesium3DTiles/PointCloud/PointCloudRGB/tileset.json';
     var pointCloudBatchedUrl = 'Data/Cesium3DTiles/PointCloud/PointCloudBatched/tileset.json';
 
+    var tilesetWithExtras = 'Data/Cesium3DTiles/Tilesets/TilesetWithExtras/tileset.json';
+
     beforeAll(function() {
         scene = createScene();
     });
@@ -356,6 +358,16 @@ defineSuite([
         });
     });
 
+    fit('loads tileset with extras', function() {
+        return Cesium3DTilesTester.loadTileset(scene, tilesetWithExtras).then(function(tileset) {
+            expect(tileset.extras).toBeDefined();
+            expect(tileset.extras).toEqual({'key': 'value'});
+
+            expect(tileset.root.extras).toBeDefined();
+            expect(tileset.root.extras).toEqual({'key': 'value'});
+        });
+    });
+
     it('gets root tile', function() {
         var tileset = scene.primitives.add(new Cesium3DTileset({
             url : tilesetUrl