Add SkBitmap StructTraits for skia::mojo::Bitmap.

ash/sysui/shelf_delegate_mus.cc

Index: ash/sysui/shelf_delegate_mus.cc
diff --git a/ash/sysui/shelf_delegate_mus.cc b/ash/sysui/shelf_delegate_mus.cc
index 1d8a4073a70a5c2cf3fd9b3dee0a2814ff75b86e..40a69115b145e4fb9a00de49f3b7a1b32cecb7b2 100644
--- a/ash/sysui/shelf_delegate_mus.cc
+++ b/ash/sysui/shelf_delegate_mus.cc
@@ -21,7 +21,6 @@
 #include "components/mus/public/cpp/window_property.h"
 #include "mojo/common/common_type_converters.h"
 #include "services/shell/public/cpp/connector.h"
-#include "skia/public/type_converters.h"
 #include "ui/aura/mus/mus_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image_skia.h"
@@ -314,7 +313,7 @@ void ShelfDelegateMus::PinItem(
   ShelfItem shelf_item;
   shelf_item.type = TYPE_APP_SHORTCUT;
   shelf_item.status = STATUS_CLOSED;
-  shelf_item.image = GetShelfIconFromBitmap(item->image.To<SkBitmap>());
+  shelf_item.image = GetShelfIconFromBitmap(item->image);
   model_->Add(shelf_item);
 
   std::unique_ptr<ShelfItemDelegateMus> item_delegate(
@@ -341,14 +340,14 @@ void ShelfDelegateMus::UnpinItem(const mojo::String& app_id) {
 }
 
 void ShelfDelegateMus::SetItemImage(const mojo::String& app_id,
-                                    skia::mojom::BitmapPtr image) {
+                                    const SkBitmap& image) {
   if (!app_id_to_shelf_id_.count(app_id.To<std::string>()))
     return;
   ShelfID shelf_id = app_id_to_shelf_id_[app_id.To<std::string>()];
   int index = model_->ItemIndexByID(shelf_id);
   DCHECK_GE(index, 0);
   ShelfItem item = *model_->ItemByID(shelf_id);
-  item.image = GetShelfIconFromBitmap(image.To<SkBitmap>());
+  item.image = GetShelfIconFromBitmap(image);
   model_->Set(index, item);
 }