Share MediaStorageUtil common code among platforms.

chrome/browser/system_monitor/removable_device_notifications_mac.mm

 // 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 "chrome/browser/system_monitor/removable_device_notifications_mac.h"
 
 #include "content/public/browser/browser_thread.h"
 
 namespace chrome {
 
 namespace {
 
+static RemovableDeviceNotificationsMac*
+    g_removable_device_notifications_mac = NULL;
+
 void GetDiskInfoAndUpdateOnFileThread(
     const base::WeakPtr<RemovableDeviceNotificationsMac>& notifications,
     base::mac::ScopedCFTypeRef<CFDictionaryRef> dict,
     RemovableDeviceNotificationsMac::UpdateType update_type) {
   DiskInfoMac info = DiskInfoMac::BuildDiskInfoOnFileThread(dict);
   if (info.device_id().empty())
     return;
 
   content::BrowserThread::PostTask(
       content::BrowserThread::UI,
@@ skipping 15 matching lines @@
       base::Bind(GetDiskInfoAndUpdateOnFileThread,
                  notifications,
                  dict,
                  update_type));
 }
 
 }  // namespace
 
 RemovableDeviceNotificationsMac::RemovableDeviceNotificationsMac() {
   session_.reset(DASessionCreate(NULL));
+  DCHECK(!g_removable_device_notifications_mac);
+  g_removable_device_notifications_mac = this;
+
   DASessionScheduleWithRunLoop(
       session_, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 
   // Register for callbacks for attached, changed, and removed devices.
   // This will send notifications for existing devices too.
   DARegisterDiskAppearedCallback(
       session_,
       kDADiskDescriptionMatchVolumeMountable,
       DiskAppearedCallback,
       this);
   DARegisterDiskDisappearedCallback(
       session_,
       kDADiskDescriptionMatchVolumeMountable,
       DiskDisappearedCallback,
       this);
   DARegisterDiskDescriptionChangedCallback(
       session_,
       kDADiskDescriptionMatchVolumeMountable,
       kDADiskDescriptionWatchVolumePath,
       DiskDescriptionChangedCallback,
       this);
 }
 
 RemovableDeviceNotificationsMac::~RemovableDeviceNotificationsMac() {
+  DCHECK_EQ(this, g_removable_device_notifications_mac);
+  g_removable_device_notifications_mac = NULL;
+
   DASessionUnscheduleFromRunLoop(
       session_, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
 }
 
+// static
+RemovableDeviceNotificationsMac*
+RemovableDeviceNotificationsMac::GetInstance() {
+  DCHECK(g_removable_device_notifications_mac != NULL);
+  return g_removable_device_notifications_mac;
+}
+
 void RemovableDeviceNotificationsMac::UpdateDisk(
     const DiskInfoMac& info,
     UpdateType update_type) {
   if (info.bsd_name().empty())
     return;
 
   std::map<std::string, DiskInfoMac>::iterator it =
       disk_info_map_.find(info.bsd_name());
   if (it != disk_info_map_.end()) {
     // If an attached notification was previously posted then post a detached
@@ skipping 92 matching lines @@
       it = disk_info_map_.begin(); it != disk_info_map_.end(); ++it) {
     if (it->second.mount_point() == mount_point) {
       *info = it->second;
       return true;
     }
   }
   return false;
 }
 
 }  // namespace chrome