Make nesting/running states a RunLoop rather than a MessageLoop concept.

ui/aura/mus/window_tree_client.cc

 // Copyright 2014 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 "ui/aura/mus/window_tree_client.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/memory/ptr_util.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "base/threading/thread.h"
 #include "cc/base/switches.h"
 #include "components/discardable_memory/client/client_discardable_shared_memory_manager.h"
 #include "mojo/public/cpp/bindings/map.h"
 #include "services/service_manager/public/cpp/connector.h"
 #include "services/ui/common/accelerator_util.h"
 #include "services/ui/public/cpp/gpu/gpu.h"
 #include "services/ui/public/cpp/property_type_converters.h"
 #include "services/ui/public/interfaces/constants.mojom.h"
 #include "services/ui/public/interfaces/window_manager.mojom.h"
@@ skipping 52 matching lines @@
   return static_cast<uint16_t>((id >> 16) & 0xFFFF);
 }
 
 struct WindowPortPropertyDataMus : public ui::PropertyData {
   std::string transport_name;
   std::unique_ptr<std::vector<uint8_t>> transport_value;
 };
 
 // Handles acknowledgment of an input event, either immediately when a nested
 // message loop starts, or upon destruction.
-class EventAckHandler : public base::MessageLoop::NestingObserver {
+class EventAckHandler : public base::RunLoop::NestingObserver {
  public:
   explicit EventAckHandler(std::unique_ptr<EventResultCallback> ack_callback)
       : ack_callback_(std::move(ack_callback)) {
     DCHECK(ack_callback_);
-    base::MessageLoop::current()->AddNestingObserver(this);
+    base::RunLoop::AddNestingObserverOnCurrentThread(this);
   }
 
   ~EventAckHandler() override {
-    base::MessageLoop::current()->RemoveNestingObserver(this);
+    base::RunLoop::RemoveNestingObserverOnCurrentThread(this);
     if (ack_callback_) {
       ack_callback_->Run(handled_ ? ui::mojom::EventResult::HANDLED
                                   : ui::mojom::EventResult::UNHANDLED);
     }
   }
 
   void set_handled(bool handled) { handled_ = handled; }
 
-  // base::MessageLoop::NestingObserver:
-  void OnBeginNestedMessageLoop() override {
+  // base::RunLoop::NestingObserver:
+  void OnBeginNestedRunLoop() override {
     // Acknowledge the event immediately if a nested message loop starts.
     // Otherwise we appear unresponsive for the life of the nested message loop.
     if (ack_callback_) {
       ack_callback_->Run(ui::mojom::EventResult::HANDLED);
       ack_callback_.reset();
     }
   }
 
  private:
   std::unique_ptr<EventResultCallback> ack_callback_;
@@ skipping 1917 matching lines @@
   return ScheduleInFlightChange(base::MakeUnique<InFlightCaptureChange>(
       this, capture_synchronizer_.get(), window));
 }
 
 uint32_t WindowTreeClient::CreateChangeIdForFocus(WindowMus* window) {
   return ScheduleInFlightChange(base::MakeUnique<InFlightFocusChange>(
       this, focus_synchronizer_.get(), window));
 }
 
 }  // namespace aura