Extend the capability of SystemMonitor to support watching storage free space change

chrome/browser/system_monitor/removable_device_notifications_linux.cc

Index: chrome/browser/system_monitor/removable_device_notifications_linux.cc
diff --git a/chrome/browser/system_monitor/removable_device_notifications_linux.cc b/chrome/browser/system_monitor/removable_device_notifications_linux.cc
index e474b36dc396287f109ed05ab41706f4a9630b8f..6df8d1093ba633c64d8418c0625f1971fcedfd54 100644
--- a/chrome/browser/system_monitor/removable_device_notifications_linux.cc
+++ b/chrome/browser/system_monitor/removable_device_notifications_linux.cc
@@ -241,6 +241,9 @@ RemovableDeviceNotificationsLinux::RemovableDeviceNotificationsLinux(
       get_device_info_func_(&GetDeviceInfo) {
   DCHECK(!g_removable_device_notifications_linux);
   g_removable_device_notifications_linux = this;
+
+  if (SystemMonitor::Get())
+    SystemMonitor::Get()->set_storage_free_space_delegate(this);
 }
 
 RemovableDeviceNotificationsLinux::RemovableDeviceNotificationsLinux(
@@ -251,12 +254,16 @@ RemovableDeviceNotificationsLinux::RemovableDeviceNotificationsLinux(
       get_device_info_func_(get_device_info_func) {
   DCHECK(!g_removable_device_notifications_linux);
   g_removable_device_notifications_linux = this;
+  if (SystemMonitor::Get())
+    SystemMonitor::Get()->set_storage_free_space_delegate(this);
 }
 
 RemovableDeviceNotificationsLinux::~RemovableDeviceNotificationsLinux() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   DCHECK_EQ(this, g_removable_device_notifications_linux);
   g_removable_device_notifications_linux = NULL;
+  if (SystemMonitor::Get())
+    SystemMonitor::Get()->set_storage_free_space_delegate(NULL);
 }
 
 // static
@@ -506,4 +513,20 @@ void RemovableDeviceNotificationsLinux::AddNewMount(
   }
 }
 
+bool RemovableDeviceNotificationsLinux::IsWatchingStorage(
+    const FilePath& path) {
+  NOTIMPLEMENTED();
+  return false;
+}
+
+void RemovableDeviceNotificationsLinux::StartWatchingStorage(
+    const FilePath& path) {
+  NOTIMPLEMENTED();
+}
+
+void RemovableDeviceNotificationsLinux::StopWatchingStorage(
+    const FilePath& path) {
+  NOTIMPLEMENTED();
+}
+
 }  // namespace chrome