Improve some debug tools for mus.

services/ui/ws/ids.h

 // 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.
 
 #ifndef SERVICES_UI_WS_IDS_H_
 #define SERVICES_UI_WS_IDS_H_
 
 #include <stdint.h>
 
+#include <string>
 #include <tuple>
 
 #include "base/containers/hash_tables.h"
 #include "base/hash.h"
+#include "base/strings/stringprintf.h"
 #include "services/ui/common/types.h"
 #include "services/ui/common/util.h"
 
 namespace ui {
 namespace ws {
 
 // A client id used to indicate no client. That is, no WindowTree ever gets this
 // id.
 const ClientSpecificId kInvalidClientId = 0;
 
@@ skipping 20 matching lines @@
     return other.client_id == client_id && other.window_id == window_id;
   }
 
   bool operator!=(const WindowId& other) const { return !(*this == other); }
 
   bool operator<(const WindowId& other) const {
     return std::tie(client_id, window_id) <
            std::tie(other.client_id, other.window_id);
   }
 
+  std::string ToString() const {
+    return base::StringPrintf("%u:%u", client_id, window_id);
+  }
+
   ClientSpecificId client_id;
   ClientSpecificId window_id;
 };
 
 // Used for ids assigned by the client.
 struct ClientWindowId {
   explicit ClientWindowId(Id id) : id(id) {}
   ClientWindowId() : id(0u) {}
 
   bool operator==(const ClientWindowId& other) const { return other.id == id; }
@@ skipping 40 matching lines @@
 template <>
 struct hash<ui::ws::WindowId> {
   size_t operator()(const ui::ws::WindowId& id) const {
     return hash<ui::Id>()(WindowIdToTransportId(id));
   }
 };
 
 }  // namespace BASE_HASH_NAMESPACE
 
 #endif  // SERVICES_UI_WS_IDS_H_