Remove FXSYS_strlen and FXSYS_wcslen

With the conversion of internal string sizes to size_t, these wrappers
are no longer needed. Replacing them with strlen and wcslen
respectively.

BUG=pdfium:828

Change-Id: Ia087ca2ddaf688a57ec9bd9ddfb8533cbe41510d
Reviewed-on: https://pdfium-review.googlesource.com/14890
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>
diff --git a/fpdfsdk/javascript/util.cpp b/fpdfsdk/javascript/util.cpp
index c4b1568..b82020d 100644
--- a/fpdfsdk/javascript/util.cpp
+++ b/fpdfsdk/javascript/util.cpp
@@ -206,7 +206,7 @@
       int iEnd;
       while ((iEnd = cFormat.find(TbConvertTable[i].lpszJSMark, iStart)) !=
              -1) {
-        cFormat.replace(iEnd, FXSYS_wcslen(TbConvertTable[i].lpszJSMark),
+        cFormat.replace(iEnd, wcslen(TbConvertTable[i].lpszJSMark),
                         TbConvertTable[i].lpszCppMark);
         iStart = iEnd;
       }
@@ -243,8 +243,7 @@
             continue;
           }
         }
-        cFormat.replace(iEnd, FXSYS_wcslen(cTableAd[i].lpszJSMark),
-                        sValue.c_str());
+        cFormat.replace(iEnd, wcslen(cTableAd[i].lpszJSMark), sValue.c_str());
         iStart = iEnd;
       }
     }