Directly inline shared WebUI CSS declarations into the security and supervised user interstitials.

ui/base/webui/web_ui_util.h

 // Copyright 2013 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.
 
 #ifndef UI_BASE_WEBUI_WEB_UI_UTIL_H_
 #define UI_BASE_WEBUI_WEB_UI_UTIL_H_
 
 #include <string>
 
 #include "base/strings/string_piece.h"
@@ skipping 29 matching lines @@
                                      float* scale_factor);
 
 // Parses a URL containing some path @{scale}x. If it does not contain a scale
 // factor then the default scale factor is returned.
 UI_BASE_EXPORT void ParsePathAndScale(const GURL& url,
                                       std::string* path,
                                       float* scale_factor);
 
 // Helper function to set the font family, size, and text direction into the
 // given dictionary.
+// Note that using font family and size in JS templates is deprecated, because
+// it might lead to flicker. Instead, use AppendWebUICSSTextDefaults() below.
+// TODO(bauerb): Remove uses of font-family and font-size in JS templates, then
+// rename this method to SetTextDirection().
 UI_BASE_EXPORT void SetFontAndTextDirection(
     base::DictionaryValue* localized_strings);
 
+// Get a CSS declaration for common text styles for all of Web UI.
+UI_BASE_EXPORT std::string GetWebUiCssTextDefaults();
+
+// Appends the CSS declaration returned by GetWebUiCssTextDefaults() as an
+// inline stylesheet.
+UI_BASE_EXPORT void AppendWebUiCssTextDefaults(std::string* html);
+
 // Get some common font styles for all of WebUI.
 UI_BASE_EXPORT std::string GetFontFamily();
 UI_BASE_EXPORT std::string GetFontSize();
 UI_BASE_EXPORT std::string GetTextDirection();
 
 }  // namespace webui
 
 #endif  // UI_BASE_WEBUI_WEB_UI_UTIL_H_