Remove TransparentActivateWindowButton from Overview Mode

ash/desktop_background/desktop_background_view.cc

Index: ash/desktop_background/desktop_background_view.cc
diff --git a/ash/desktop_background/desktop_background_view.cc b/ash/desktop_background/desktop_background_view.cc
index 4ffc3e11f32c1f48151b0a8c77777f9cafa5af6c..1fa424bcf6f8ef0a4b4a94339a3f6532db36906d 100644
--- a/ash/desktop_background/desktop_background_view.cc
+++ b/ash/desktop_background/desktop_background_view.cc
@@ -15,7 +15,6 @@
 #include "ash/session/session_state_delegate.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
-#include "ash/wm/overview/window_selector_controller.h"
 #include "ash/wm/window_animations.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/utf_string_conversions.h"
@@ -78,51 +77,14 @@ class LayerControlView : public views::View {
 
 }  // namespace
 
-// This event handler receives events in the pre-target phase and takes care of
-// the following:
-//   - Disabling overview mode on touch release.
-//   - Disabling overview mode on mouse release.
-class PreEventDispatchHandler : public ui::EventHandler {
- public:
-  PreEventDispatchHandler() {}
-  ~PreEventDispatchHandler() override {}
-
- private:
-  // ui::EventHandler:
-  void OnMouseEvent(ui::MouseEvent* event) override {
-    CHECK_EQ(ui::EP_PRETARGET, event->phase());
-    WindowSelectorController* controller =
-        Shell::GetInstance()->window_selector_controller();
-    if (event->type() == ui::ET_MOUSE_RELEASED && controller->IsSelecting()) {
-      controller->ToggleOverview();
-      event->StopPropagation();
-    }
-  }
-
-  void OnGestureEvent(ui::GestureEvent* event) override {
-    CHECK_EQ(ui::EP_PRETARGET, event->phase());
-    WindowSelectorController* controller =
-        Shell::GetInstance()->window_selector_controller();
-    if (event->type() == ui::ET_GESTURE_TAP && controller->IsSelecting()) {
-      controller->ToggleOverview();
-      event->StopPropagation();
-    }
-  }
-
-  DISALLOW_COPY_AND_ASSIGN(PreEventDispatchHandler);
-};
-
 ////////////////////////////////////////////////////////////////////////////////
 // DesktopBackgroundView, public:
 
-DesktopBackgroundView::DesktopBackgroundView()
-    : pre_dispatch_handler_(new PreEventDispatchHandler()) {
+DesktopBackgroundView::DesktopBackgroundView() {
   set_context_menu_controller(this);
-  AddPreTargetHandler(pre_dispatch_handler_.get());
 }
 
 DesktopBackgroundView::~DesktopBackgroundView() {
-  RemovePreTargetHandler(pre_dispatch_handler_.get());
 }
 
 ////////////////////////////////////////////////////////////////////////////////