Break up Control class

src/System.Windows.Forms/src/System/Windows/Forms/ButtonInternal/CheckableControlBaseAdapter.cs

@@ -89,8 +89,7 @@ internal static double GetDpiScaleRatio(Graphics g, Control control)
             if (DpiHelper.IsPerMonitorV2Awareness
                 && control != null && control.IsHandleCreated)
             {
-
-                return control.deviceDpi / DpiHelper.LogicalDpi;
+                return control._deviceDpi / DpiHelper.LogicalDpi;
             }
 
             if (g == null)

src/System.Windows.Forms/src/System/Windows/Forms/ComboBox.cs

@@ -6317,7 +6317,7 @@ public FlatComboAdapter(ComboBox comboBox, bool smallButton)
                 Offset2Pixels = comboBox.LogicalToDeviceUnits(OFFSET_2PIXELS);
 
                 clientRect = comboBox.ClientRectangle;
-                int dropDownButtonWidth = SystemInformation.GetHorizontalScrollBarArrowWidthForDpi(comboBox.deviceDpi);
+                int dropDownButtonWidth = SystemInformation.GetHorizontalScrollBarArrowWidthForDpi(comboBox._deviceDpi);
                 outerBorder = new Rectangle(clientRect.Location, new Size(clientRect.Width - 1, clientRect.Height - 1));
                 innerBorder = new Rectangle(outerBorder.X + 1, outerBorder.Y + 1, outerBorder.Width - dropDownButtonWidth - 2, outerBorder.Height - 2);
                 innerInnerBorder = new Rectangle(innerBorder.X + 1, innerBorder.Y + 1, innerBorder.Width - 2, innerBorder.Height - 2);

src/System.Windows.Forms/src/System/Windows/Forms/ContainerControl.cs

@@ -319,7 +319,7 @@ public SizeF CurrentAutoScaleDimensions
                             // Screen Dpi
                             if (DpiHelper.IsPerMonitorV2Awareness)
                             {
-                                _currentAutoScaleDimensions = new SizeF((float)deviceDpi, (float)deviceDpi);
+                                _currentAutoScaleDimensions = new SizeF((float)_deviceDpi, (float)_deviceDpi);
                             }
                             else
                             {

src/System.Windows.Forms/src/System/Windows/Forms/Control.ActiveXFontMarshaler.cs

@@ -0,0 +1,96 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Drawing;
+using System.Runtime.InteropServices;
+
+namespace System.Windows.Forms
+{
+    public partial class Control
+    {
+        /// <summary>
+        ///  This is a marshaler object that knows how to marshal IFont to Font
+        ///  and back.
+        /// </summary>
+        private class ActiveXFontMarshaler : ICustomMarshaler
+        {
+            private static ActiveXFontMarshaler s_instance;
+
+            public void CleanUpManagedData(object obj)
+            {
+            }
+
+            public void CleanUpNativeData(IntPtr pObj)
+            {
+                Marshal.Release(pObj);
+            }
+
+            internal static ICustomMarshaler GetInstance(string cookie)
+            {
+                if (s_instance == null)
+                {
+                    s_instance = new ActiveXFontMarshaler();
+                }
+                return s_instance;
+            }
+
+            public int GetNativeDataSize()
+                => -1; // not a value type, so use -1
+
+            public IntPtr MarshalManagedToNative(object obj)
+            {
+                Font font = (Font)obj;
+                NativeMethods.tagFONTDESC fontDesc = new NativeMethods.tagFONTDESC();
+                NativeMethods.LOGFONTW logFont = NativeMethods.LOGFONTW.FromFont(font);
+
+                fontDesc.lpstrName = font.Name;
+                fontDesc.cySize = (long)(font.SizeInPoints * 10000);
+                fontDesc.sWeight = (short)logFont.lfWeight;
+                fontDesc.sCharset = logFont.lfCharSet;
+                fontDesc.fItalic = font.Italic;
+                fontDesc.fUnderline = font.Underline;
+                fontDesc.fStrikethrough = font.Strikeout;
+
+                Guid iid = typeof(UnsafeNativeMethods.IFont).GUID;
+
+                UnsafeNativeMethods.IFont oleFont = UnsafeNativeMethods.OleCreateFontIndirect(fontDesc, ref iid);
+                IntPtr pFont = Marshal.GetIUnknownForObject(oleFont);
+
+                int hr = Marshal.QueryInterface(pFont, ref iid, out IntPtr pIFont);
+
+                Marshal.Release(pFont);
+
+                if (NativeMethods.Failed(hr))
+                {
+                    Marshal.ThrowExceptionForHR(hr);
+                }
+
+                return pIFont;
+            }
+
+            public object MarshalNativeToManaged(IntPtr pObj)
+            {
+                UnsafeNativeMethods.IFont nativeFont = (UnsafeNativeMethods.IFont)Marshal.GetObjectForIUnknown(pObj);
+                IntPtr hfont = nativeFont.GetHFont();
+
+                Font font;
+                try
+                {
+                    font = Font.FromHfont(hfont);
+                }
+                catch (Exception e)
+                {
+                    if (ClientUtils.IsSecurityOrCriticalException(e))
+                    {
+                        throw;
+                    }
+
+                    font = DefaultFont;
+                }
+
+                return font;
+            }
+        }
+    }
+}