Make it possible to run Sky apps offline

sky/shell/linux/main.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/at_exit.h"
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/i18n/icu_util.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "sky/shell/platform_view.h"
 #include "sky/shell/service_provider.h"
 #include "sky/shell/shell.h"
 #include "sky/shell/shell_view.h"
 
 namespace sky {
 namespace shell {
 
+const char kMain[] = "main";
+const char kPackageRoot[] = "package-root";
+
 void Init() {
   Shell::Init(make_scoped_ptr(new ServiceProviderContext(
       base::MessageLoop::current()->task_runner())));
 
   // TODO(abarth): Currently we leak the ShellView.
   ShellView* shell_view = new ShellView(Shell::Shared());
 
   ViewportObserverPtr viewport_observer;
   shell_view->view()->ConnectToViewportObserver(GetProxy(&viewport_observer));
 
-  // TODO(abarth): At this point we should load some content into the view.
-  // viewport_observer->LoadURL("https://domokit.github.io/home.dart");
+  base::CommandLine& command_line = *base::CommandLine::ForCurrentProcess();
+
+  std::string main = command_line.GetSwitchValueASCII(kMain);
+  std::string package_root = command_line.GetSwitchValueASCII(kPackageRoot);
+
+  viewport_observer->RunFromFile(main, package_root);
 }
 
 } // namespace shell
 } // namespace sky
 
 int main(int argc, const char* argv[]) {
   base::AtExitManager exit_manager;
   base::CommandLine::Init(argc, argv);
 
   base::MessageLoop message_loop;
 
   base::i18n::InitializeICU();
 
   message_loop.PostTask(FROM_HERE, base::Bind(&sky::shell::Init));
   message_loop.Run();
 
   return 0;
 }