Converts Widget::SetOpacity from char to float

ui/views/mus/native_widget_mus.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/mus/native_widget_mus.h"
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 1042 matching lines @@
         break;
     }
   }
 }
 
 bool NativeWidgetMus::IsFullscreen() const {
   return mus_window_observer_ &&
       mus_window_observer_->show_state() == mus::mojom::ShowState::FULLSCREEN;
 }
 
-void NativeWidgetMus::SetOpacity(unsigned char opacity) {
+void NativeWidgetMus::SetOpacity(float opacity) {
   if (window_)
-    window_->SetOpacity(opacity / 255.0);
+    window_->SetOpacity(opacity);
 }
 
 void NativeWidgetMus::FlashFrame(bool flash_frame) {
   // NOTIMPLEMENTED();
 }
 
 void NativeWidgetMus::RunShellDrag(
     View* view,
     const ui::OSExchangeData& data,
     const gfx::Point& location,
@@ skipping 283 matching lines @@
 
   gfx::Path mask_path;
   native_widget_delegate_->GetHitTestMask(&mask_path);
   // TODO(jamescook): Use the full path for the mask.
   gfx::Rect mask_rect =
       gfx::ToEnclosingRect(gfx::SkRectToRectF(mask_path.getBounds()));
   window_->SetHitTestMask(mask_rect);
 }
 
 }  // namespace views