Fix compilation error on Windows.

samples/pdfium_test.cc

 // Copyright (c) 2010 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 <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <list>
@@ skipping 428 matching lines @@
   for (int i = 0; i < page_count; ++i) {
     FPDF_PAGE page = FPDF_LoadPage(doc, i);
     if (!page) {
         bad_pages ++;
         continue;
     }
     FPDF_TEXTPAGE text_page = FPDFText_LoadPage(page);
     FORM_OnAfterLoadPage(page, form);
     FORM_DoPageAAction(page, form, FPDFPAGE_AACTION_OPEN);
 
-    int width = static_cast<int>(FPDF_GetPageWidth(page));
-    int height = static_cast<int>(FPDF_GetPageHeight(page));
+    double scale = 1.0;
     if (!options.scale_factor_as_string.empty()) {
-      double scale = 1.0;
       std::stringstream(options.scale_factor_as_string) >> scale;
-      width *= scale;
-      height *= scale;
     }
+    int width = static_cast<int>(FPDF_GetPageWidth(page) * scale);
+    int height = static_cast<int>(FPDF_GetPageHeight(page) * scale);
 
     FPDF_BITMAP bitmap = FPDFBitmap_Create(width, height, 0);
     FPDFBitmap_FillRect(bitmap, 0, 0, width, height, 0xFFFFFFFF);
     FPDF_RenderPageBitmap(bitmap, page, 0, 0, width, height, 0, 0);
     rendered_pages ++;
 
     FPDF_FFLDraw(form, bitmap, page, 0, 0, width, height, 0, 0);
     int stride = FPDFBitmap_GetStride(bitmap);
     const char* buffer =
         reinterpret_cast<const char*>(FPDFBitmap_GetBuffer(bitmap));
@@ skipping 86 matching lines @@
     RenderPdf(filename, file_contents, file_length, options);
     free(file_contents);
   }
 
   FPDF_DestroyLibrary();
   v8::V8::ShutdownPlatform();
   delete platform;
 
   return 0;
 }