clang/win: Let some chromium_code targets build with -Wextra.

content/browser/system_message_window_win.cc

 // Copyright (c) 2012 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/browser/system_message_window_win.h"
 
 #include <dbt.h>
 
 #include "base/logging.h"
 #include "base/system_monitor/system_monitor.h"
@@ skipping 27 matching lines @@
   }
 
   void Register(HWND hwnd) {
     // Request to receive device notifications.  All applications receive basic
     // notifications via WM_DEVICECHANGE but in order to receive detailed device
     // arrival and removal messages, we need to register.
     DEV_BROADCAST_DEVICEINTERFACE filter = {0};
     filter.dbcc_size = sizeof(filter);
     filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
     bool core_audio_support = media::CoreAudioUtil::IsSupported();
-    for (int i = 0; i < arraysize(kDeviceCategoryMap); ++i) {
+    for (size_t i = 0; i < arraysize(kDeviceCategoryMap); ++i) {
       // If CoreAudio is supported, AudioDeviceListenerWin will
       // take care of monitoring audio devices.
       if (core_audio_support &&
           KSCATEGORY_AUDIO == kDeviceCategoryMap[i].device_category) {
         continue;
       }
 
       filter.dbcc_classguid = kDeviceCategoryMap[i].device_category;
       DCHECK_EQ(notifications_[i], static_cast<HDEVNOTIFY>(NULL));
       notifications_[i] = RegisterDeviceNotification(
           hwnd, &filter, DEVICE_NOTIFY_WINDOW_HANDLE);
       DPLOG_IF(ERROR, !notifications_[i])
           << "RegisterDeviceNotification failed";
     }
   }
 
   void Unregister() {
-    for (int i = 0; i < arraysize(notifications_); ++i) {
+    for (size_t i = 0; i < arraysize(notifications_); ++i) {
       if (notifications_[i]) {
         UnregisterDeviceNotification(notifications_[i]);
         notifications_[i] = NULL;
       }
     }
   }
 
  private:
   HDEVNOTIFY notifications_[arraysize(kDeviceCategoryMap)];
 
@@ skipping 38 matching lines @@
     case DBT_DEVICEARRIVAL: {
       // This notification has more details about the specific device that
       // was added or removed.  See if this is a category we're interested
       // in monitoring and if so report the specific device type.  If we don't
       // find the category in our map, ignore the notification and do not
       // notify the system monitor.
       DEV_BROADCAST_DEVICEINTERFACE* device_interface =
           reinterpret_cast<DEV_BROADCAST_DEVICEINTERFACE*>(data);
       if (device_interface->dbcc_devicetype != DBT_DEVTYP_DEVICEINTERFACE)
         return TRUE;
-      for (int i = 0; i < arraysize(kDeviceCategoryMap); ++i) {
+      for (size_t i = 0; i < arraysize(kDeviceCategoryMap); ++i) {
         if (kDeviceCategoryMap[i].device_category ==
             device_interface->dbcc_classguid) {
           device_type = kDeviceCategoryMap[i].device_type;
           break;
         }
       }
 
       // Devices that we do not have a DEVTYPE_ for, get detected via
       // DBT_DEVNODES_CHANGED, so we avoid sending additional notifications
       // for those here.
@@ skipping 17 matching lines @@
     case WM_DEVICECHANGE:
       return OnDeviceChange(static_cast<UINT>(wparam), lparam);
     default:
       break;
   }
 
   return ::DefWindowProc(hwnd, message, wparam, lparam);
 }
 
 }  // namespace content