Upstream the iOS web_shell and supporting code

ios/web/app/web_main_loop.h

Index: ios/web/app/web_main_loop.h
diff --git a/ios/web/app/web_main_loop.h b/ios/web/app/web_main_loop.h
new file mode 100644
index 0000000000000000000000000000000000000000..8fd9178efabe667792249f28985f3e06e9aad00b
--- /dev/null
+++ b/ios/web/app/web_main_loop.h
@@ -0,0 +1,99 @@
+// Copyright 2014 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.
+
+#ifndef IOS_WEB_APP_WEB_MAIN_LOOP_H_
+#define IOS_WEB_APP_WEB_MAIN_LOOP_H_
+
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+
+namespace base {
+class CommandLine;
+class FilePath;
+class MessageLoop;
+class PowerMonitor;
+class SystemMonitor;
+}  // namespace base
+
+namespace net {
+class NetworkChangeNotifier;
+}  // namespace net
+
+namespace web {
+class CookieNotificationBridge;
+class WebMainParts;
+class WebThreadImpl;
+
+// Implements the main web loop stages called from WebMainRunner.
+// See comments in web_main_parts.h for additional info.
+class WebMainLoop {
+ public:
+  explicit WebMainLoop();
+  virtual ~WebMainLoop();
+
+  void Init();
+
+  void EarlyInitialization();
+  void MainMessageLoopStart();
+
+  // Creates and starts running the tasks needed to complete startup.
+  void CreateStartupTasks();
+
+  // Performs the shutdown sequence, starting with PostMainMessageLoopRun
+  // through stopping threads to PostDestroyThreads.
+  void ShutdownThreadsAndCleanUp();
+
+  int GetResultCode() const { return result_code_; }
+
+ private:
+  void InitializeMainThread();
+
+  // Called just before creating the threads
+  int PreCreateThreads();
+
+  // Creates all secondary threads.
+  int CreateThreads();
+
+  // Called right after the web threads have been started.
+  int WebThreadsStarted();
+
+  // Called just before attaching to the main message loop.
+  int PreMainMessageLoopRun();
+
+  // Members initialized on construction ---------------------------------------
+  int result_code_;
+  // True if the non-UI threads were created.
+  bool created_threads_;
+
+  // Members initialized in |MainMessageLoopStart()| ---------------------------
+  scoped_ptr<base::MessageLoop> main_message_loop_;
+  scoped_ptr<base::SystemMonitor> system_monitor_;
+  scoped_ptr<base::PowerMonitor> power_monitor_;
+  scoped_ptr<net::NetworkChangeNotifier> network_change_notifier_;
+
+  // Destroy parts_ before main_message_loop_ (required) and before other
+  // classes constructed in web (but after main_thread_).
+  scoped_ptr<WebMainParts> parts_;
+
+  // Members initialized in |InitializeMainThread()| ---------------------------
+  // This must get destroyed before other threads that are created in parts_.
+  scoped_ptr<WebThreadImpl> main_thread_;
+
+  // Members initialized in |RunMainMessageLoopParts()| ------------------------
+  scoped_ptr<WebThreadImpl> db_thread_;
+  scoped_ptr<WebThreadImpl> file_user_blocking_thread_;
+  scoped_ptr<WebThreadImpl> file_thread_;
+  scoped_ptr<WebThreadImpl> cache_thread_;
+  scoped_ptr<WebThreadImpl> io_thread_;
+
+  // Members initialized in |WebThreadsStarted()| --------------------------
+  scoped_ptr<CookieNotificationBridge> cookie_notification_bridge_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebMainLoop);
+};
+
+}  // namespace web
+
+#endif  // IOS_WEB_APP_WEB_MAIN_LOOP_H_