android: Java-based launcher thread

base/android/java_handler_thread.h

Index: base/android/java_handler_thread.h
diff --git a/base/android/java_handler_thread.h b/base/android/java_handler_thread.h
index 96f2f0a1dcfee7657285eb9d11c5a408d6283671..25fd3409760a627881f0639bf895d0e897008f10 100644
--- a/base/android/java_handler_thread.h
+++ b/base/android/java_handler_thread.h
@@ -24,7 +24,12 @@ namespace android {
 // 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(); }