Add ContextMenuSourceType to views::ContextMenuController::ShowContextMenuForView.

ui/views/controls/button/button_dropdown.cc

Index: ui/views/controls/button/button_dropdown.cc
diff --git a/ui/views/controls/button/button_dropdown.cc b/ui/views/controls/button/button_dropdown.cc
index a243cee1917c4a0aa01e377bdf9d168218f1a012..23453d75a69f87b1bafbdcccf84548fe9c5bcf8b 100644
--- a/ui/views/controls/button/button_dropdown.cc
+++ b/ui/views/controls/button/button_dropdown.cc
@@ -132,7 +132,8 @@ void ButtonDropDown::GetAccessibleState(ui::AccessibleViewState* state) {
 }
 
 void ButtonDropDown::ShowContextMenuForView(View* source,
-                                            const gfx::Point& point) {
+                                            const gfx::Point& point,
+                                            ui::MenuSourceType source_type) {
   if (!enabled())
     return;
 
@@ -191,6 +192,7 @@ void ButtonDropDown::ShowDropDownMenu() {
         menu_runner_->RunMenuAt(GetWidget(), NULL,
                                 gfx::Rect(menu_position, gfx::Size(0, 0)),
                                 MenuItemView::TOPLEFT,
+                                ui::MENU_SOURCE_NONE,
                                 MenuRunner::HAS_MNEMONICS);
     if (result == MenuRunner::MENU_DELETED)
       return;
@@ -202,6 +204,7 @@ void ButtonDropDown::ShowDropDownMenu() {
         menu_runner_->RunMenuAt(GetWidget(), NULL,
                                 gfx::Rect(menu_position, gfx::Size(0, 0)),
                                 MenuItemView::TOPLEFT,
+                                ui::MENU_SOURCE_NONE,
                                 MenuRunner::HAS_MNEMONICS);
     if (result == MenuRunner::MENU_DELETED)
       return;