mus: Fix handled status in UI event ack, add MessageLoop::NestingObserver

base/message_loop/message_loop.cc

 // 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.
 
 #include "base/message_loop/message_loop.h"
 
 #include <algorithm>
 #include <memory>
 #include <utility>
 
@@ skipping 103 matching lines @@
 
 MessageLoop::TaskObserver::TaskObserver() {
 }
 
 MessageLoop::TaskObserver::~TaskObserver() {
 }
 
 MessageLoop::DestructionObserver::~DestructionObserver() {
 }
 
+MessageLoop::NestingObserver::~NestingObserver() {}
+
 //------------------------------------------------------------------------------
 
 MessageLoop::MessageLoop(Type type)
     : MessageLoop(type, MessagePumpFactoryCallback()) {
   BindToCurrentThread();
 }
 
 MessageLoop::MessageLoop(std::unique_ptr<MessagePump> pump)
     : MessageLoop(TYPE_CUSTOM, Bind(&ReturnPump, Passed(&pump))) {
   BindToCurrentThread();
@@ skipping 122 matching lines @@
   DCHECK_EQ(this, current());
   destruction_observers_.AddObserver(destruction_observer);
 }
 
 void MessageLoop::RemoveDestructionObserver(
     DestructionObserver* destruction_observer) {
   DCHECK_EQ(this, current());
   destruction_observers_.RemoveObserver(destruction_observer);
 }
 
+void MessageLoop::AddNestingObserver(NestingObserver* observer) {
+  DCHECK_EQ(this, current());
+  nesting_observers_.AddObserver(observer);
+}
+
+void MessageLoop::RemoveNestingObserver(NestingObserver* observer) {
+  DCHECK_EQ(this, current());
+  nesting_observers_.RemoveObserver(observer);
+}
+
 void MessageLoop::PostTask(
     const tracked_objects::Location& from_here,
     const Closure& task) {
   task_runner_->PostTask(from_here, task);
 }
 
 void MessageLoop::PostDelayedTask(
     const tracked_objects::Location& from_here,
     const Closure& task,
     TimeDelta delay) {
@@ skipping 293 matching lines @@
 #endif
 }
 
 void MessageLoop::HistogramEvent(int event) {
 #if !defined(OS_NACL)
   if (message_histogram_)
     message_histogram_->Add(event);
 #endif
 }
 
+void MessageLoop::NotifyBeginNestedLoop() {
+  FOR_EACH_OBSERVER(NestingObserver, nesting_observers_,
+                    OnBeginNestedMessageLoop());
+}
+
 bool MessageLoop::DoWork() {
   if (!nestable_tasks_allowed_) {
     // Task can't be executed right now.
     return false;
   }
 
   for (;;) {
     ReloadWorkQueue();
     if (work_queue_.empty())
       break;
@@ skipping 159 matching lines @@
       persistent,
       mode,
       controller,
       delegate);
 }
 #endif
 
 #endif  // !defined(OS_NACL_SFI)
 
 }  // namespace base