Properly throw java exceptions from shouldOverrideUrlLoading

base/android/java_handler_thread.cc

Index: base/android/java_handler_thread.cc
diff --git a/base/android/java_handler_thread.cc b/base/android/java_handler_thread.cc
index 75270348e6ee15756daa12faf09303d53b5b903a..ed5cb95f21babe8da0c9e33e98d6f70d377960b5 100644
--- a/base/android/java_handler_thread.cc
+++ b/base/android/java_handler_thread.cc
@@ -35,8 +35,7 @@ void JavaHandlerThread::Start() {
   base::WaitableEvent initialize_event(
       WaitableEvent::ResetPolicy::AUTOMATIC,
       WaitableEvent::InitialState::NOT_SIGNALED);
-  Java_JavaHandlerThread_start(env,
-                               java_thread_.obj(),
+  Java_JavaHandlerThread_start(env, java_thread_.obj(),
                                reinterpret_cast<intptr_t>(this),
                                reinterpret_cast<intptr_t>(&initialize_event));
   // Wait for thread to be initialized so it is ready to be used when Start
@@ -63,17 +62,25 @@ void JavaHandlerThread::InitializeThread(JNIEnv* env,
                                          jlong event) {
   // TYPE_JAVA to get the Android java style message loop.
   message_loop_.reset(new base::MessageLoop(base::MessageLoop::TYPE_JAVA));
-  static_cast<MessageLoopForUI*>(message_loop_.get())->Start();
+  StartMessageLoop();
   reinterpret_cast<base::WaitableEvent*>(event)->Signal();
 }
 
 void JavaHandlerThread::StopThread(JNIEnv* env,
                                    const JavaParamRef<jobject>& obj,
                                    jlong event) {
-  static_cast<MessageLoopForUI*>(message_loop_.get())->QuitWhenIdle();
+  StopMessageLoop();
   reinterpret_cast<base::WaitableEvent*>(event)->Signal();
 }
 
+void JavaHandlerThread::StartMessageLoop() {
+  static_cast<MessageLoopForUI*>(message_loop_.get())->Start();
+}
+
+void JavaHandlerThread::StopMessageLoop() {
+  static_cast<MessageLoopForUI*>(message_loop_.get())->QuitWhenIdle();
+}
+
 // static
 bool JavaHandlerThread::RegisterBindings(JNIEnv* env) {
   return RegisterNativesImpl(env);