[MD settings] disable clear browsing data while it is running

chrome/browser/browsing_data/browsing_data_remover.cc

Index: chrome/browser/browsing_data/browsing_data_remover.cc
diff --git a/chrome/browser/browsing_data/browsing_data_remover.cc b/chrome/browser/browsing_data/browsing_data_remover.cc
index a877c0390ad500a80d003c141a10fec7f1a33948..522b09901048e371652e70d741a96a74afbb0ed9 100644
--- a/chrome/browser/browsing_data/browsing_data_remover.cc
+++ b/chrome/browser/browsing_data/browsing_data_remover.cc
@@ -346,6 +346,8 @@ void BrowsingDataRemover::Shutdown() {
 void BrowsingDataRemover::SetRemoving(bool is_removing) {
   DCHECK_NE(is_removing_, is_removing);
   is_removing_ = is_removing;
+  FOR_EACH_OBSERVER(Observer, observer_list_,
+                    OnBrowsingDataRemoving(is_removing));
 }
 
 void BrowsingDataRemover::Remove(const TimeRange& time_range,