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..cd6650270bb65754aec76ea467d769b000901b9f 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(
@@ -257,6 +260,9 @@ 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()->storage_free_space_delegate())
+    SystemMonitor::Get()->set_storage_free_space_delegate(NULL);
 }
 
 // static
@@ -356,6 +362,9 @@ void RemovableDeviceNotificationsLinux::InitOnFileThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   initialized_ = true;
 
+  if (SystemMonitor::Get())
+    SystemMonitor::Get()->set_storage_free_space_delegate(this);
+
   // The callback passed to Watch() has to be unretained. Otherwise
   // RemovableDeviceNotificationsLinux will live longer than expected, and
   // FilePathWatcher will get in trouble at shutdown time.
@@ -506,4 +515,14 @@ void RemovableDeviceNotificationsLinux::AddNewMount(
   }
 }
 
+void RemovableDeviceNotificationsLinux::StartWatchingStorage(
+    const FilePath& path) {
+  NOTIMPLEMENTED();
+}
+
+void RemovableDeviceNotificationsLinux::StopWatchingStorage(
+    const FilePath& path) {
+  NOTIMPLEMENTED();
+}
+
 }  // namespace chrome