Fix "unused variable" warnings.

ui/views/test/native_widget_factory_desktop.cc

 // Copyright 2016 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/test/native_widget_factory.h"
 
 #if defined(USE_AURA)
 #include "ui/views/widget/native_widget_aura.h"
 #if !defined(OS_CHROMEOS)
 #include "ui/views/widget/desktop_aura/desktop_native_widget_aura.h"
@@ skipping 15 matching lines @@
 
 namespace {
 
 class TestPlatformDesktopNativeWidget : public PlatformDesktopNativeWidget {
  public:
   TestPlatformDesktopNativeWidget(internal::NativeWidgetDelegate* delegate,
                                   bool* destroyed);
   ~TestPlatformDesktopNativeWidget() override;
 
  private:
-  bool mouse_capture_;
   bool* destroyed_;
 
   DISALLOW_COPY_AND_ASSIGN(TestPlatformDesktopNativeWidget);
 };
 
 // A widget that assumes mouse capture always works. It won't in testing, so we
 // mock it.
 TestPlatformDesktopNativeWidget::TestPlatformDesktopNativeWidget(
     internal::NativeWidgetDelegate* delegate,
     bool* destroyed)
@@ skipping 15 matching lines @@
 #if defined(OS_CHROMEOS)
   // Chromeos only has one NativeWidgetType.
   return CreatePlatformNativeWidgetImpl(init_params, widget, 0u, destroyed);
 #else
   return new TestPlatformDesktopNativeWidget(widget, destroyed);
 #endif
 }
 
 }  // namespace test
 }  // namespace views