Disable pinch-to-zoom gesture on virtual keyboard

ui/keyboard/keyboard_controller.cc

Index: ui/keyboard/keyboard_controller.cc
diff --git a/ui/keyboard/keyboard_controller.cc b/ui/keyboard/keyboard_controller.cc
index 638bd29f149b5923f4552bbd8fa47c6c7f70a058..86e3822eeca8f44547935865316751e53b6cf9c4 100644
--- a/ui/keyboard/keyboard_controller.cc
+++ b/ui/keyboard/keyboard_controller.cc
@@ -188,6 +188,7 @@ KeyboardController::~KeyboardController() {
     if (container_->GetRootWindow())
       container_->GetRootWindow()->RemoveObserver(this);
     container_->RemoveObserver(this);
+    container_->RemovePreTargetHandler(&event_filter_);
   }
   if (input_method_)
     input_method_->RemoveObserver(this);
@@ -216,6 +217,7 @@ aura::Window* KeyboardController::GetContainerWindow() {
     container_->Init(ui::LAYER_NOT_DRAWN);
     container_->AddObserver(this);
     container_->SetLayoutManager(new KeyboardLayoutManager(this));
+    container_->AddPreTargetHandler(&event_filter_);
   }
   return container_.get();
 }