Making a way to create thread with a Java Looper for Android

base/message_loop/message_loop.h

 // Copyright 2013 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 BASE_MESSAGE_LOOP_MESSAGE_LOOP_H_
 #define BASE_MESSAGE_LOOP_MESSAGE_LOOP_H_
 
 #include <queue>
 #include <string>
 
@@ skipping 91 matching lines @@
   //   This type of ML only supports tasks and timers.
   //
   // TYPE_UI
   //   This type of ML also supports native UI events (e.g., Windows messages).
   //   See also MessageLoopForUI.
   //
   // TYPE_IO
   //   This type of ML also supports asynchronous IO.  See also
   //   MessageLoopForIO.
   //
+  // TYPE_JAVA
+  //   This type of ML is backed by a Java message handler which is responsible
+  //   for running the tasks added to the ML. This is only for use on Android.
+  //
   enum Type {
     TYPE_DEFAULT,
     TYPE_UI,
-    TYPE_IO
+    TYPE_IO,
+#if defined(OS_ANDROID)
+    TYPE_JAVA,
+#endif // defined(OS_ANDROID)
   };
 
   // Normally, it is not necessary to instantiate a MessageLoop.  Instead, it
   // is typical to make use of the current thread's MessageLoop instance.
   explicit MessageLoop(Type type = TYPE_DEFAULT);
   virtual ~MessageLoop();
 
   // Returns the MessageLoop object for the current thread, or null if none.
   static MessageLoop* current();
 
@@ skipping 575 matching lines @@
 
 // Do not add any member variables to MessageLoopForIO!  This is important b/c
 // MessageLoopForIO is often allocated via MessageLoop(TYPE_IO).  Any extra
 // data that you need should be stored on the MessageLoop's pump_ instance.
 COMPILE_ASSERT(sizeof(MessageLoop) == sizeof(MessageLoopForIO),
                MessageLoopForIO_should_not_have_extra_member_variables);
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_LOOP_MESSAGE_LOOP_H_