Add test data for spaceport benchmark.

chrome/test/data/third_party/spaceport/js/sprites/sources.js

+(function () {
+    var names = [
+        'image',
+        //'spriteSheet'
+    ];
+
+    var filenames = [ ];
+    names.forEach(function (name) {
+        filenames.push('sprites/sources/' + name);
+    });
+
+    define(filenames, function (/* ... */) {
+        var sources = { };
+        var values = arguments;
+        names.forEach(function (name, i) {
+            sources[name] = values[i];
+        });
+
+        return sources;
+    });
+}());