Add a policy to disable mounting of external storage.

chrome/browser/chromeos/extensions/file_browser_event_router.cc

Index: chrome/browser/chromeos/extensions/file_browser_event_router.cc
diff --git a/chrome/browser/chromeos/extensions/file_browser_event_router.cc b/chrome/browser/chromeos/extensions/file_browser_event_router.cc
index 78a9e2701e0cd02c3dd4ab483efb9c0eccb97c1e..be09f77b3b3c5a2b5f40ad65534677eeff059347 100644
--- a/chrome/browser/chromeos/extensions/file_browser_event_router.cc
+++ b/chrome/browser/chromeos/extensions/file_browser_event_router.cc
@@ -29,6 +29,7 @@
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/notification_source.h"
 #include "grit/generated_resources.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "webkit/fileapi/file_system_types.h"
 #include "webkit/fileapi/file_system_util.h"
 
@@ -155,6 +156,7 @@ void FileBrowserEventRouter::ObserveFileSystemEvents() {
   pref_change_registrar_->Add(prefs::kDisableGDataOverCellular, this);
   pref_change_registrar_->Add(prefs::kDisableGDataHostedFiles, this);
   pref_change_registrar_->Add(prefs::kDisableGData, this);
+  pref_change_registrar_->Add(prefs::kExternalStorageDisabled, this);
 }
 
 // File watch setup routines.
@@ -344,9 +346,30 @@ void FileBrowserEventRouter::Observe(
     NOTREACHED();
     return;
   }
-  profile_->GetExtensionEventRouter()->DispatchEventToRenderers(
-      extensions::event_names::kOnFileBrowserGDataPreferencesChanged,
-      "[]", NULL, GURL());
+  if (type == chrome::NOTIFICATION_PREF_CHANGED) {
+    std::string* pref_name = content::Details<std::string>(details).ptr();
+    // If the policy just got disabled we have to unmount every device currently
+    // mounted. The opposite is fine - we can let the user re-plug her device to
+    // make it available.
+    if (*pref_name == prefs::kExternalStorageDisabled &&
+        profile_->GetPrefs()->GetBoolean(prefs::kExternalStorageDisabled)) {
+      DiskMountManager *manager = DiskMountManager::GetInstance();
+      DiskMountManager::MountPointMap mounts(manager->mount_points());
+      for (DiskMountManager::MountPointMap::const_iterator it = mounts.begin();
+           it != mounts.end(); ++it) {
+        LOG(INFO) << "Unmounting " << it->second.mount_path
+                  << " because of policy.";
+        manager->UnmountPath(it->second.mount_path);
+      }
+      return;
+    } else if (*pref_name == prefs::kDisableGDataOverCellular ||
+        *pref_name == prefs::kDisableGDataHostedFiles ||
+        *pref_name == prefs::kDisableGData) {
+      profile_->GetExtensionEventRouter()->DispatchEventToRenderers(
+          extensions::event_names::kOnFileBrowserGDataPreferencesChanged,
+          "[]", NULL, GURL());
+    }
+  }
 }
 
 void FileBrowserEventRouter::OnProgressUpdate(
@@ -546,8 +569,10 @@ void FileBrowserEventRouter::OnDiskAdded(
     return;
   }
 
-  // If disk is not mounted yet and it has media, give it a try.
-  if (disk->mount_path().empty() && disk->has_media()) {
+  // If disk is not mounted yet and it has media and there is no policy
+  // forbidding external storage, give it a try.
+  if (disk->mount_path().empty() && disk->has_media() &&
+      !profile_->GetPrefs()->GetBoolean(prefs::kExternalStorageDisabled)) {
     // Initiate disk mount operation. MountPath auto-detects the filesystem
     // format if the second argument is empty. The third argument (mount label)
     // is not used in a disk mount operation.
@@ -581,6 +606,16 @@ void FileBrowserEventRouter::OnDeviceAdded(
 
   VLOG(1) << "Device added : " << device_path;
 
+  // If the policy is set instead of showing the new device notification we show
+  // a notification that the operation is not permitted.
+  if (profile_->GetPrefs()->GetBoolean(prefs::kExternalStorageDisabled)) {
+    notifications_->ShowNotificationWithMessage(
+        FileBrowserNotifications::DEVICE_FAIL,
+        device_path,
+        l10n_util::GetStringUTF16(IDS_EXTERNAL_STORAGE_DISABLED_MESSAGE));
+    return;
+  }
+
   notifications_->RegisterDevice(device_path);
   notifications_->ShowNotificationDelayed(FileBrowserNotifications::DEVICE,
                                           device_path,