Add ContainsKey() and ContainsValue() and use them where appropriate.

fpdfsdk/src/javascript/util.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "util.h"
 
 #include "JS_Context.h"
 #include "JS_Define.h"
@@ skipping 450 matching lines @@
         break;
       }
       case '*': {
         cPurpose.append(cSource, itSource, iSize - itSource);
         itSource = iSize - 1;
         break;
       }
       case '\\':
         break;
       case '>': {
-        for (std::string::iterator it = cSource.begin(); it != cSource.end();
-             it++) {
-          *it = toupper(*it);
-        }
+        for (char& c : cSource)
+          c = toupper(c);
         break;
       }
       case '<': {
-        for (std::string::iterator it = cSource.begin(); it != cSource.end();
-             it++) {
-          *it = tolower(*it);
-        }
+        for (char& c : cSource)
+          c = tolower(c);
         break;
       }
       case '=':
         break;
       default:
         cPurpose += letter;
         break;
     }
   }
 }
@@ skipping 53 matching lines @@
   int iSize = params.size();
   if (iSize == 0)
     return FALSE;
   int nByte = params[0].ToInt();
   unsigned char cByte = (unsigned char)nByte;
   CFX_WideString csValue;
   csValue.Format(L"%c", cByte);
   vRet = csValue.c_str();
   return TRUE;
 }