mash: Support ShelfModel access in Chrome.

ash/shelf/shelf_view.cc

Index: ash/shelf/shelf_view.cc
diff --git a/ash/shelf/shelf_view.cc b/ash/shelf/shelf_view.cc
index b8c65bc101c8aeac9c4d8efd7ee74bc451e6d508..c78d81f4619cb160428fefccae5dc31ba109f4d8 100644
--- a/ash/shelf/shelf_view.cc
+++ b/ash/shelf/shelf_view.cc
@@ -9,6 +9,7 @@
 
 #include "ash/ash_constants.h"
 #include "ash/drag_drop/drag_image_view.h"
+#include "ash/public/cpp/config.h"
 #include "ash/public/cpp/shelf_item_delegate.h"
 #include "ash/scoped_root_window_for_new_windows.h"
 #include "ash/screen_util.h"
@@ -464,10 +465,21 @@ void ShelfView::ButtonPressed(views::Button* sender,
 
   // Notify the item of its selection; handle the result in AfterItemSelected.
   const ShelfItem& item = model_->items()[last_pressed_index_];
+  // Mash requires conversion of mouse and touch events to pointer events.
+  std::unique_ptr<ui::Event> passed_event = ui::Event::Clone(event);
+  if (Shell::GetAshConfig() == Config::MASH &&
+      ui::PointerEvent::CanConvertFrom(event)) {
+    if (event.IsMouseEvent())
+      passed_event = base::MakeUnique<ui::PointerEvent>(*event.AsMouseEvent());
+    else if (event.IsTouchEvent())
+      passed_event = base::MakeUnique<ui::PointerEvent>(*event.AsTouchEvent());
+    else
+      NOTREACHED() << "Need conversion of event to pointer event.";
+  }
   model_->GetShelfItemDelegate(item.id)->ItemSelected(
-      ui::Event::Clone(event), display_id, LAUNCH_FROM_UNKNOWN,
+      ui::Event::Clone(*passed_event), display_id, LAUNCH_FROM_UNKNOWN,

[James Cook, 2017/05/30 22:47:47]

Can you avoid cloning the event twice? Maybe move the Clone() inside the if()
and/or add an else?

[msw, 2017/05/31 16:55:21]

Done. This miserable client code is a sign of poor infrastructure. I pinged
Sadrul and Hadi about mus not supporting mouse/touch events, but that seems to
be their intended design for now.

       base::Bind(&ShelfView::AfterItemSelected, weak_factory_.GetWeakPtr(),
-                 item, sender, base::Passed(ui::Event::Clone(event)),
+                 item, sender, base::Passed(ui::Event::Clone(*passed_event)),
                  ink_drop));
 }
 
@@ -1596,6 +1608,9 @@ void ShelfView::ShelfItemMoved(int start_index, int target_index) {
     AnimateToIdealBounds();
 }
 
+void ShelfView::ShelfItemDelegateChanged(const ShelfID& id,
+                                         ShelfItemDelegate* delegate) {}
+
 void ShelfView::AfterItemSelected(
     const ShelfItem& item,
     views::Button* sender,