Changes look for scrollbars on windows (2)

ui/native_theme/native_theme_win.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/native_theme/native_theme_win.h"
 
 #include <windows.h>
 #include <uxtheme.h>
 #include <vsstyle.h>
 #include <vssym32.h>
@@ skipping 215 matching lines @@
 
 gfx::Size NativeThemeWin::GetPartSize(Part part,
                                       State state,
                                       const ExtraParams& extra) const {
   gfx::Size part_size = CommonThemeGetPartSize(part, state, extra);
   if (!part_size.IsEmpty())
     return part_size;
 
   // The GetThemePartSize call below returns the default size without
   // accounting for user customization (crbug/218291).
-  SIZE size;
   switch (part) {
     case kScrollbarDownArrow:
     case kScrollbarLeftArrow:
     case kScrollbarRightArrow:
     case kScrollbarUpArrow:
     case kScrollbarHorizontalThumb:
     case kScrollbarVerticalThumb:
     case kScrollbarHorizontalTrack:
-    case kScrollbarVerticalTrack:
-      size.cx = size.cy = gfx::win::GetSystemMetricsInDIP(SM_CXVSCROLL);
-      return gfx::Size(size.cx, size.cy);
+    case kScrollbarVerticalTrack: {
+      int size = gfx::win::GetSystemMetricsInDIP(SM_CXVSCROLL);
+      if (size == 0)
+        size = 17;
+      return gfx::Size(size, size);
+    }
   }
 
   int part_id = GetWindowsPart(part, state, extra);
   int state_id = GetWindowsState(part, state, extra);
 
+  SIZE size;
   HDC hdc = GetDC(NULL);
   HRESULT hr = GetThemePartSize(GetThemeName(part), hdc, part_id, state_id,
                                 NULL, TS_TRUE, &size);
   ReleaseDC(NULL, hdc);
 
   if (FAILED(hr)) {
     // TODO(rogerta): For now, we need to support radio buttons and checkboxes
     // when theming is not enabled.  Support for other parts can be added
     // if/when needed.
     switch (part) {
@@ skipping 1826 matching lines @@
     handle = open_theme_(NULL, L"Spin");
     break;
   default:
     NOTREACHED();
   }
   theme_handles_[theme_name] = handle;
   return handle;
 }
 
 }  // namespace ui