Widget opacity goes from 0 to 1, not 0 to 255.

ash/drag_drop/drag_image_view.cc

Index: ash/drag_drop/drag_image_view.cc
diff --git a/ash/drag_drop/drag_image_view.cc b/ash/drag_drop/drag_image_view.cc
index 97c0e18111f7bbf5414033f4166c954a477ce538..fb8a432906c24fa3d2e7284956617d77da20d294 100644
--- a/ash/drag_drop/drag_image_view.cc
+++ b/ash/drag_drop/drag_image_view.cc
@@ -28,7 +28,7 @@ Widget* CreateDragWidget(gfx::NativeView context) {
   params.ownership = Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
   params.opacity = Widget::InitParams::TRANSLUCENT_WINDOW;
   drag_widget->Init(params);
-  drag_widget->SetOpacity(0xFF);
+  drag_widget->SetOpacity(1.f);
   drag_widget->GetNativeWindow()->set_owned_by_parent(false);
   drag_widget->GetNativeWindow()->SetName("DragWidget");
   SetShadowType(drag_widget->GetNativeView(), wm::SHADOW_TYPE_NONE);
@@ -99,7 +99,7 @@ void DragImageView::SetTouchDragOperationHintPosition(
 void DragImageView::SetOpacity(float visibility) {
   DCHECK_GE(visibility, 0.0f);
   DCHECK_LE(visibility, 1.0f);
-  widget_->SetOpacity(static_cast<int>(0xff * visibility));
+  widget_->SetOpacity(visibility);
 }
 
 void DragImageView::OnPaint(gfx::Canvas* canvas) {