android: Java-based launcher thread

base/test/android/java_handler_thread_for_testing.h

 // Copyright 2016 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_FOR_TESTING_H_
 #define BASE_ANDROID_JAVA_HANDLER_THREAD_FOR_TESTING_H_
 
 #include "base/android/java_handler_thread.h"
 #include "base/android/java_message_handler_factory.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 20 matching lines @@
 // does.
 // This is partly because we need to create a test-only java-side message
 // handler to back the native message loop, and partly because our tests cause
 // the corresponding message pump to abort which means it won't reach its idle
 // work state and thus can't quit when idle. We here stop the pump more abruptly
 // instead.
 class JavaHandlerThreadForTesting : public JavaHandlerThread {
  public:
   JavaHandlerThreadForTesting(const char* name,
                               base::WaitableEvent* test_done_event);
+  // Create java peer first, then connect with native.
+  explicit JavaHandlerThreadForTesting(base::WaitableEvent* test_done_event);
   ~JavaHandlerThreadForTesting() override;
 
   void StartMessageLoop() override;
   void StopMessageLoop() override;
 
  private:
   std::unique_ptr<JavaMessageHandlerFactory> message_handler_factory_;
   base::WaitableEvent* test_done_event_;
 };
 
 }  // namespace android
 }  // namespace base
 
 #endif  // BASE_ANDROID_JAVA_HANDLER_THREAD_FOR_TESTING_H_