Converts Widget::SetOpacity from char to float

ui/views/widget/native_widget_aura.cc

 // Copyright (c) 2012 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/widget/native_widget_aura.h"
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/string_util.h"
 #include "build/build_config.h"
@@ skipping 586 matching lines @@
   window_->SetProperty(
       aura::client::kShowStateKey,
       fullscreen ? ui::SHOW_STATE_FULLSCREEN : saved_window_state_);
 }
 
 bool NativeWidgetAura::IsFullscreen() const {
   return window_ && window_->GetProperty(aura::client::kShowStateKey) ==
       ui::SHOW_STATE_FULLSCREEN;
 }
 
-void NativeWidgetAura::SetOpacity(unsigned char opacity) {
+void NativeWidgetAura::SetOpacity(float opacity) {
   if (window_)
-    window_->layer()->SetOpacity(opacity / 255.0);
+    window_->layer()->SetOpacity(opacity);
 }
 
 void NativeWidgetAura::FlashFrame(bool flash) {
   if (window_)
     window_->SetProperty(aura::client::kDrawAttentionKey, flash);
 }
 
 void NativeWidgetAura::RunShellDrag(View* view,
                                     const ui::OSExchangeData& data,
                                     const gfx::Point& location,
@@ skipping 572 matching lines @@
     gfx::NativeView native_view) {
   aura::client::CaptureClient* capture_client =
       aura::client::GetCaptureClient(native_view->GetRootWindow());
   if (!capture_client)
     return nullptr;
   return capture_client->GetGlobalCaptureWindow();
 }
 
 }  // namespace internal
 }  // namespace views