Remove candidate show/hide/update related code

ui/views/controls/prefix_selector.cc

Index: ui/views/controls/prefix_selector.cc
diff --git a/ui/views/controls/prefix_selector.cc b/ui/views/controls/prefix_selector.cc
index c4e2240231614bf7b1fe313284b246cc9d4aee6b..f7e8f66fa833828cf983972e85d568a92445b2f4 100644
--- a/ui/views/controls/prefix_selector.cc
+++ b/ui/views/controls/prefix_selector.cc
@@ -138,15 +138,6 @@ void PrefixSelector::ExtendSelectionAndDelete(size_t before, size_t after) {
 void PrefixSelector::EnsureCaretInRect(const gfx::Rect& rect) {
 }
 
-void PrefixSelector::OnCandidateWindowShown() {
-}
-
-void PrefixSelector::OnCandidateWindowUpdated() {
-}
-
-void PrefixSelector::OnCandidateWindowHidden() {
-}
-
 bool PrefixSelector::IsEditCommandEnabled(int command_id) {
   return false;
 }