added CTRL+Click and SHIFT+Click handler for context menu, Back and Forward.

ui/base/models/simple_menu_model.cc

Index: ui/base/models/simple_menu_model.cc
diff --git a/ui/base/models/simple_menu_model.cc b/ui/base/models/simple_menu_model.cc
index 28c1b01c444d35d172d0d38be39f47c542c7d475..d975dd28b5ca2ce7db64f2276856f0958abe7461 100644
--- a/ui/base/models/simple_menu_model.cc
+++ b/ui/base/models/simple_menu_model.cc
@@ -49,6 +49,11 @@ void SimpleMenuModel::Delegate::CommandIdHighlighted(int command_id) {
 void SimpleMenuModel::Delegate::MenuClosed() {
 }
 
+void SimpleMenuModel::Delegate::ExecuteCommandWithDisposition(
+    int command_id, int disposition) {
+  ExecuteCommand(command_id);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // SimpleMenuModel, public:
 
@@ -287,6 +292,12 @@ void SimpleMenuModel::ActivatedAt(int index) {
     delegate_->ExecuteCommand(GetCommandIdAt(index));
 }
 
+void SimpleMenuModel::ActivatedAtWithDisposition(int index, int disposition) {
+  if (delegate_)
+    delegate_->ExecuteCommandWithDisposition(GetCommandIdAt(index),
+                                             disposition);
+}
+
 MenuModel* SimpleMenuModel::GetSubmenuModelAt(int index) const {
   return items_.at(FlipIndex(index)).submenu;
 }