ozone/platform/wayland: Use more realistic event processing and request flushing in tests

ui/ozone/platform/wayland/wayland_display.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 UI_OZONE_PLATFORM_WAYLAND_WAYLAND_DISPLAY_H_
 #define UI_OZONE_PLATFORM_WAYLAND_WAYLAND_DISPLAY_H_
 
 #include <map>
 
 #include "base/message_loop/message_pump_libevent.h"
 #include "ui/events/platform/platform_event_source.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/ozone/platform/wayland/wayland_object.h"
 
 namespace ui {
 
 class WaylandWindow;
 
 class WaylandDisplay : public PlatformEventSource,
                        public base::MessagePumpLibevent::Watcher {
  public:
   WaylandDisplay();
   ~WaylandDisplay() override;
 
   bool Initialize();
+  bool StartProcessingEvents();
 
-  // Flushes the Wayland connection.
-  void Flush();
+  // Schedules a flush of the Wayland connection.
+  void ScheduleFlush();
 
   wl_display* display() { return display_.get(); }
   wl_compositor* compositor() { return compositor_.get(); }
   wl_shm* shm() { return shm_.get(); }
   xdg_shell* shell() { return shell_.get(); }
 
   WaylandWindow* GetWindow(gfx::AcceleratedWidget widget);
   void AddWindow(gfx::AcceleratedWidget widget, WaylandWindow* window);
   void RemoveWindow(gfx::AcceleratedWidget widget);
 
  private:
+  void Flush();
+
   // PlatformEventSource
   void OnDispatcherListChanged() override;
 
   // base::MessagePumpLibevent::Watcher
   void OnFileCanReadWithoutBlocking(int fd) override;
   void OnFileCanWriteWithoutBlocking(int fd) override;
 
   // wl_registry_listener
   static void Global(void* data,
                      wl_registry* registry,
                      uint32_t name,
                      const char* interface,
                      uint32_t version);
   static void GlobalRemove(void* data, wl_registry* registry, uint32_t name);
 
   // xdg_shell_listener
   static void Ping(void* data, xdg_shell* shell, uint32_t serial);
 
   std::map<gfx::AcceleratedWidget, WaylandWindow*> window_map_;
 
   wl::Object<wl_display> display_;
   wl::Object<wl_registry> registry_;
   wl::Object<wl_compositor> compositor_;
   wl::Object<wl_shm> shm_;
   wl::Object<xdg_shell> shell_;
 
+  bool scheduled_flush_ = false;
   bool watching_ = false;
   base::MessagePumpLibevent::FileDescriptorWatcher controller_;
 
   DISALLOW_COPY_AND_ASSIGN(WaylandDisplay);
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_WAYLAND_WAYLAND_DISPLAY_H_