Update from chromium https://crrev.com/301315

net/base/escape.h

 // 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.
 
 #ifndef NET_BASE_ESCAPE_H_
 #define NET_BASE_ESCAPE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 24 matching lines @@
 // Space is escaped as + (if use_plus is true) and other special characters
 // as %XX (hex).
 NET_EXPORT std::string EscapeUrlEncodedData(const std::string& path,
                                             bool use_plus);
 
 // Escapes all non-ASCII input.
 NET_EXPORT std::string EscapeNonASCII(const std::string& input);
 
 // Escapes characters in text suitable for use as an external protocol handler
 // command.
-// We %XX everything except alphanumerics and %-_.!~*'() and the restricted
-// chracters (;/?:@&=+$,).
+// We %XX everything except alphanumerics and -_.!~*'() and the restricted
+// chracters (;/?:@&=+$,#[]) and a valid percent escape sequence (%XX).
 NET_EXPORT std::string EscapeExternalHandlerValue(const std::string& text);
 
 // Appends the given character to the output string, escaping the character if
 // the character would be interpretted as an HTML delimiter.
 NET_EXPORT void AppendEscapedCharForHTML(char c, std::string* output);
 
 // Escapes chars that might cause this text to be interpretted as HTML tags.
 NET_EXPORT std::string EscapeForHTML(const std::string& text);
 NET_EXPORT base::string16 EscapeForHTML(const base::string16& text);
 
@@ skipping 72 matching lines @@
     UnescapeRule::Type rules,
     base::OffsetAdjuster::Adjustments* adjustments);
 
 // Unescapes the following ampersand character codes from |text|:
 // &lt; &gt; &amp; &quot; &#39;
 NET_EXPORT base::string16 UnescapeForHTML(const base::string16& text);
 
 }  // namespace net
 
 #endif  // NET_BASE_ESCAPE_H_