Guarded shrink setting with ifdefs to make clear where it is used.

printing/printed_page.cc

 // Copyright (c) 2011 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 "printing/printed_page.h"
 
 namespace printing {
 
 PrintedPage::PrintedPage(int page_number,
                          Metafile* metafile,
                          const gfx::Size& page_size,
-                         const gfx::Rect& page_content_rect,
-                         double shrink_factor)
+                         const gfx::Rect& page_content_rect)
     : page_number_(page_number),
       metafile_(metafile),
+#if defined(OS_WIN)
+      shrink_factor_(0.0f),
+#endif  // OS_WIN
       page_size_(page_size),
-      page_content_rect_(page_content_rect),
-      shrink_factor_(shrink_factor) {
+      page_content_rect_(page_content_rect) {
 }
 
 PrintedPage::~PrintedPage() {
 }
 
 const Metafile* PrintedPage::metafile() const {
   return metafile_.get();
 }
 
 void PrintedPage::GetCenteredPageContentRect(
     const gfx::Size& paper_size, gfx::Rect* content_rect) const {
   *content_rect = page_content_rect();
   if (paper_size.width() > page_size().width()) {
     int diff = paper_size.width() - page_size().width();
     content_rect->set_x(content_rect->x() + diff / 2);
   }
   if (paper_size.height() > page_size().height()) {
     int diff = paper_size.height() - page_size().height();
     content_rect->set_y(content_rect->y() + diff / 2);
   }
 }
 
 }  // namespace printing