Add base::RunLoop and update ui_test_utils to use it to reduce flakiness

base/message_pump_android.cc

 // Copyright (c) 2012 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.
 
 #include "base/message_pump_android.h"
 
 #include <jni.h>
 
 #include "base/android/jni_android.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
+#include "base/run_loop.h"
 #include "jni/system_message_handler_jni.h"
 
 using base::android::ScopedJavaLocalRef;
 
 namespace {
 
 base::LazyInstance<base::android::ScopedJavaGlobalRef<jobject> >
     g_system_message_handler_obj = LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
@@ skipping 31 matching lines @@
     jlong millis =
         (delayed_work_time - base::TimeTicks::Now()).InMillisecondsRoundedUp();
     Java_SystemMessageHandler_setDelayedTimer(env, obj, millis);
   }
   return more_work_is_plausible;
 }
 
 namespace base {
 
 MessagePumpForUI::MessagePumpForUI()
-    : state_(NULL) {
+    : run_loop_(NULL) {
 }
 
 MessagePumpForUI::~MessagePumpForUI() {
 }
 
 void MessagePumpForUI::Run(Delegate* delegate) {
   NOTREACHED() << "UnitTests should rely on MessagePumpForUIStub in"
       " test_stub_android.h";
 }
 
 void MessagePumpForUI::Start(Delegate* delegate) {
-  state_ = new MessageLoop::AutoRunState(MessageLoop::current());
+  run_loop_ = new base::RunLoop();
+  // Since the RunLoop was just created above, BeforeRun should be guaranteed to
+  // return true (it only returns false if the RunLoop has been Quit already).
+  if (!run_loop_->BeforeRun())
+    NOTREACHED();
 
   DCHECK(g_system_message_handler_obj.Get().is_null());
 
   JNIEnv* env = base::android::AttachCurrentThread();
   DCHECK(env);
 
   g_system_message_handler_obj.Get().Reset(
       Java_SystemMessageHandler_create(env, reinterpret_cast<jint>(delegate)));
 }
 
 void MessagePumpForUI::Quit() {
   if (!g_system_message_handler_obj.Get().is_null()) {
     JNIEnv* env = base::android::AttachCurrentThread();
     DCHECK(env);
 
     Java_SystemMessageHandler_removeTimer(env,
         g_system_message_handler_obj.Get().obj());
     g_system_message_handler_obj.Get().Reset();
   }
 
-  if (state_) {
-    delete state_;
-    state_ = NULL;
+  if (run_loop_) {
+    run_loop_->AfterRun();
+    delete run_loop_;
+    run_loop_ = NULL;
   }
 }
 
 void MessagePumpForUI::ScheduleWork() {
   if (g_system_message_handler_obj.Get().is_null())
     return;
 
   JNIEnv* env = base::android::AttachCurrentThread();
   DCHECK(env);
 
@@ skipping 15 matching lines @@
   Java_SystemMessageHandler_setDelayedTimer(env,
       g_system_message_handler_obj.Get().obj(), millis);
 }
 
 // Register native methods
 bool RegisterSystemMessageHandler(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace base