Update AuraWindowRegistry to create only positive window IDs.

content/public/browser/desktop_media_id.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 "content/public/browser/desktop_media_id.h"
 
 #include <vector>
 
 #include "base/memory/singleton.h"
 #include "base/strings/string_split.h"
@@ skipping 14 matching lines @@
   }
 
   int RegisterWindow(aura::Window* window) {
     // First check if an Id is already assigned to the |window|.
     std::map<aura::Window*, int>::iterator it = window_to_id_map_.find(window);
     if (it != window_to_id_map_.end()) {
       return it->second;
     }
 
     // If the windows doesn't have an Id yet assign it.
-    int id = next_id_++;
+    int id;
+    do {
+      id = next_id_;
+      next_id_ = (next_id_ == INT_MAX) ? 1 : (next_id_ + 1);
+    } while (id_to_window_map_.find(id) != id_to_window_map_.end());
+
     window_to_id_map_[window] = id;
     id_to_window_map_[id] = window;
     window->AddObserver(this);
     return id;
   }
 
   aura::Window* GetWindowById(int id) {
     std::map<int, aura::Window*>::iterator it = id_to_window_map_.find(id);
     return (it != id_to_window_map_.end()) ? it->second : NULL;
   }
 
  private:
   friend struct DefaultSingletonTraits<AuraWindowRegistry>;
 
   AuraWindowRegistry()
-      : next_id_(0) {
+      : next_id_(1) {
   }
   virtual ~AuraWindowRegistry() {}
 
   // WindowObserver overrides.
   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE {
     std::map<aura::Window*, int>::iterator it = window_to_id_map_.find(window);
     DCHECK(it != window_to_id_map_.end());
     id_to_window_map_.erase(it->second);
     window_to_id_map_.erase(it);
   }
@@ skipping 76 matching lines @@
   }
   DCHECK(!prefix.empty());
 
   prefix.append(":");
   prefix.append(base::Int64ToString(id));
 
   return prefix;
 }
 
 }  // namespace content