Fix help and error messages.

tools/gn/pattern.cc

 // Copyright (c) 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.
 
 #include "tools/gn/pattern.h"
 
 #include "tools/gn/value.h"
 
 const char kPattern_Help[] =
     "Patterns\n"
     "  Patterns are VERY limited regular expressions that are used in\n"
     "  several places.\n"
     "\n"
     "  Patterns must match the entire input string to be counted as a match.\n"
     "  In regular expression parlance, there is an implicit \"^...$\"\n"
     "  surrounding your input. If you want to match a substring, you need to\n"
     "  use wildcards at the beginning and end.\n"
     "\n"
     "  There are only two special tokens understood by the pattern matcher.\n"
     "  Everything else is a literal.\n"
     "\n"
     "   * Matches zero or more of any character. It does not depend on the\n"
-    "     preceeding character (in regular expression parlance it is\n"
+    "     preceding character (in regular expression parlance it is\n"
     "     equivalent to \".*\").\n"
     "\n"
     "  \\b Matches a path boundary. This will match the beginning or end of\n"
     "     a string, or a slash.\n"
     "\n"
     "Examples\n"
     "\n"
     "  \"*asdf*\"\n"
     "      Matches a string containing \"asdf\" anywhere.\n"
     "\n"
@@ skipping 180 matching lines @@
       return true;
   }
   return false;
 }
 
 bool PatternList::MatchesValue(const Value& v) const {
   if (v.type() == Value::STRING)
     return MatchesString(v.string_value());
   return false;
 }