Load stocks data off the network

Instead of hard-coding the stock data in the Dart file, this CL moves the data
to a JSON file and loads that file over the network. This change improves load
time for the Stocks app from 3 seconds to 2 seconds.

Also, this CL removes shake-to-reload from the Stocks app because that also
slows down load time (due to the two module systems fighting each other).

R=rafaelw@chromium.org, ojan@chromium.org

Review URL: https://codereview.chromium.org/1021723005

examples/stocks-fn/lib/stock_app.dart

@@ -33,14 +33,18 @@ class StocksApp extends App {
     ${typography.white.title};'''
   );
 
-  List<Stock> _sortedStocks;
+  List<Stock> _sortedStocks = [];
   bool _isSearching = false;
   bool _isShowingMenu = false;
   String _searchQuery;
 
   StocksApp() : super() {
+    fetchStockOracle().then((oracle) {
+      setState(() {
         _sortedStocks = oracle.stocks;
         _sortedStocks.sort((a, b) => a.symbol.compareTo(b.symbol));
+      });
+    });
   }
 
   void _handleSearchClick(_) {

examples/stocks-fn/main.sky

@@ -5,7 +5,6 @@
 // found in the LICENSE file.
 -->
 <sky>
-<import src="/sky/framework/debug/shake-to-reload.sky" />
 <script>
 // TODO(abarth): Should this be package:stocks/stocks_app.dart?
 import 'lib/stock_app.dart';