Add APIs for limited use of document tagged code.

public/fpdf_formfill.h

Index: public/fpdf_formfill.h
diff --git a/public/fpdf_formfill.h b/public/fpdf_formfill.h
index ada87d3158beeedac40eef83eda16fb319e4f93c..09b80eaf90b7734e4dcaeb90efe222b2e7dd0922 100644
--- a/public/fpdf_formfill.h
+++ b/public/fpdf_formfill.h
@@ -149,10 +149,8 @@ typedef struct _IPDF_JsPlatform {
   *       The filePath should be always input in local encoding.
   *
   *       The return value always indicated number of bytes required for the
-  * buffer, even when there is
-  *       no buffer specified, or the buffer size is less then required. In this
-  * case, the buffer will not
-  *       be modified.
+  *       buffer , even when there is no buffer specified, or the buffer size is
+  *       less than required. In this case, the buffer will not be modified.
   */
   int (*Doc_getFilePath)(struct _IPDF_JsPlatform* pThis,
                          void* filePath,