Cleanup: Mark methods with the override keyword.

fpdfsdk/src/formfiller/FFL_ComboBox.cpp

Index: fpdfsdk/src/formfiller/FFL_ComboBox.cpp
diff --git a/fpdfsdk/src/formfiller/FFL_ComboBox.cpp b/fpdfsdk/src/formfiller/FFL_ComboBox.cpp
index b49726d5abdfff63bd1f215e2f8dd0fd5522b20e..29352216ab3af87b296d3c9835d1c046a7ed0f32 100644
--- a/fpdfsdk/src/formfiller/FFL_ComboBox.cpp
+++ b/fpdfsdk/src/formfiller/FFL_ComboBox.cpp
@@ -300,24 +300,6 @@ void CFFL_ComboBox::OnKillFocus(CPWL_Wnd* pWnd) {
   ASSERT(m_pApp != NULL);
 }
 
-FX_BOOL CFFL_ComboBox::CanCopy(CPDFSDK_Document* pDocument) {
-  ASSERT(pDocument != NULL);
-
-  return FALSE;
-}
-
-FX_BOOL CFFL_ComboBox::CanCut(CPDFSDK_Document* pDocument) {
-  ASSERT(pDocument != NULL);
-
-  return FALSE;
-}
-
-FX_BOOL CFFL_ComboBox::CanPaste(CPDFSDK_Document* pDocument) {
-  ASSERT(pDocument != NULL);
-
-  return FALSE;
-}
-
 void CFFL_ComboBox::OnAddUndo(CPWL_Edit* pEdit) {
   ASSERT(pEdit != NULL);
 }