Resolve all but two VC++ build warnings in pdfium.

core/src/fpdftext/fpdf_text_int.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 "../../include/fpdfapi/fpdf_resource.h"
 #include "../../include/fpdfapi/fpdf_pageobj.h"
 #include "../../include/fpdftext/fpdf_text.h"
 #include "../../include/fpdfapi/fpdf_page.h"
@@ skipping 19 matching lines @@
             || curChar == 8467
             || (curChar >= 0x2000 && curChar <= 0x206F)) {
         return FALSE;
     }
     return TRUE;
 }
 
 FX_FLOAT _NormalizeThreshold(FX_FLOAT threshold)
 {
     if (threshold < 300) {
-        return threshold / 2.0;
+        return threshold / 2.0f;
     } else if (threshold < 500) {
-        return threshold / 4.0;
+        return threshold / 4.0f;
     } else if (threshold < 700) {
-        return threshold / 5.0;
+        return threshold / 5.0f;
     }
-    return threshold / 6.0;
+    return threshold / 6.0f;
 }
 
 FX_FLOAT _CalculateBaseSpace(const CPDF_TextObject* pTextObj,
                              const CFX_AffineMatrix& matrix)
 {
     FX_FLOAT baseSpace = 0.0;
     const int nItems = pTextObj->CountItems();
     if (pTextObj->m_TextState.GetObject()->m_CharSpace && nItems >= 3) {
         FX_BOOL bAllChar = TRUE;
         FX_FLOAT spacing = matrix.TransformDistance(
@@ skipping 2793 matching lines @@
     if (!m_IsParserd || index < 0 || index >= m_LinkList.GetSize()) {
         return;
     }
     CPDF_LinkExt* link = NULL;
     link = m_LinkList.GetAt(index);
     if (!link) {
         return ;
     }
     m_pTextPage->GetRectArray(link->m_Start, link->m_Count, rects);
 }