android: Java-based launcher thread

base/android/java_handler_thread.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_ANDROID_JAVA_HANDLER_THREAD_H_
 #define BASE_ANDROID_JAVA_HANDLER_THREAD_H_
 
 #include <jni.h>
 
 #include <memory>
 
 #include "base/android/scoped_java_ref.h"
 
 namespace base {
 
 class MessageLoop;
 
 namespace android {
 
 // A Java Thread with a native message loop. To run tasks, post them
 // to the message loop and they will be scheduled along with Java tasks
 // on the thread.
 // This is useful for callbacks where the receiver expects a thread
 // with a prepared Looper.
 class BASE_EXPORT JavaHandlerThread {
  public:
-  JavaHandlerThread(const char* name);
+  // Create new thread.
+  explicit JavaHandlerThread(const char* name);
+  // Wrap and connect to an existing JavaHandlerThread.
+  // |obj| is an instance of JavaHandlerThread.
+  explicit JavaHandlerThread(
+      const base::android::ScopedJavaLocalRef<jobject>& obj);
   virtual ~JavaHandlerThread();
 
   base::MessageLoop* message_loop() const { return message_loop_.get(); }
   void Start();
   void Stop();
 
   // Called from java on the newly created thread.
   // Start() will not return before this methods has finished.
   void InitializeThread(JNIEnv* env,
                         const JavaParamRef<jobject>& obj,
@@ skipping 11 matching lines @@
   std::unique_ptr<base::MessageLoop> message_loop_;
 
  private:
   ScopedJavaGlobalRef<jobject> java_thread_;
 };
 
 }  // namespace android
 }  // namespace base
 
 #endif  // BASE_ANDROID_JAVA_HANDLER_THREAD_H_