Refactor ViewsDelegate and MD-ify the icon-to-text spacing for checkbox and radiobutton

chrome/browser/ui/views/chrome_views_delegate_win.cc

 // Copyright 2017 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 "chrome/browser/ui/views/chrome_views_delegate.h"
 
 #include <dwmapi.h>
 #include <shellapi.h>
 
 #include "base/profiler/scoped_tracker.h"
@@ skipping 86 matching lines @@
     edges |= views::ViewsDelegate::EDGE_LEFT;
   if (MonitorHasAutohideTaskbarForEdge(ABE_TOP, monitor))
     edges |= views::ViewsDelegate::EDGE_TOP;
   if (MonitorHasAutohideTaskbarForEdge(ABE_RIGHT, monitor))
     edges |= views::ViewsDelegate::EDGE_RIGHT;
   if (MonitorHasAutohideTaskbarForEdge(ABE_BOTTOM, monitor))
     edges |= views::ViewsDelegate::EDGE_BOTTOM;
   return edges;
 }
 
+ChromeViewsDelegate* views_delegate = nullptr;
+
 }  // namespace
 
 ChromeViewsDelegate::ChromeViewsDelegate()
-    : in_autohide_edges_callback_(false), weak_factory_(this) {}
+    : in_autohide_edges_callback_(false), weak_factory_(this) {
+  DCHECK(!views_delegate);
+  views_delegate = this;
+}
+
+ChromeViewsDelegate::~ChromeViewsDelegate() {
+  DCHECK_EQ(0u, ref_count_);
+
+  DCHECK_EQ(this, views_delegate);
+  views_delegate = nullptr;
+}
+
+ChromeViewsDelegate* ChromeViewsDelegate::GetInstance() {
+  return views_delegate;
+}
 
 HICON ChromeViewsDelegate::GetDefaultWindowIcon() const {
   return GetAppIcon();
 }
 
 HICON ChromeViewsDelegate::GetSmallWindowIcon() const {
   return GetSmallAppIcon();
 }
 
 views::NativeWidget* ChromeViewsDelegate::CreateNativeWidget(
@@ skipping 65 matching lines @@
     HMONITOR monitor,
     int returned_edges,
     int edges) {
   appbar_autohide_edge_map_[monitor] = edges;
   if (returned_edges == edges)
     return;
 
   base::AutoReset<bool> in_callback_setter(&in_autohide_edges_callback_, true);
   callback.Run();
 }