Quick fix for linux shared build.

printing/page_overlays.cc

Index: printing/page_overlays.cc
diff --git a/printing/page_overlays.cc b/printing/page_overlays.cc
index 946186dc3bd657dec7df24961e55bf99445dfde8..e590490cf01dec54bd39931d5a90efc46795d162 100644
--- a/printing/page_overlays.cc
+++ b/printing/page_overlays.cc
@@ -137,6 +137,9 @@ std::wstring PageOverlays::ReplaceVariables(const std::wstring& input,
                                             const PrintedDocument& document,
                                             const PrintedPage& page) {
   std::wstring output(input);
+// Prevent references to document.page_count() on Linux until
+// printed_document.cc is included in printing.gyp.
+#if !defined(OS_LINUX)
   for (size_t offset = output.find(L'{', 0);
        offset != std::wstring::npos;
        offset = output.find(L'{', offset)) {
@@ -200,6 +203,7 @@ std::wstring PageOverlays::ReplaceVariables(const std::wstring& input,
       ++offset;
     }
   }
+#endif // !defined(OS_LINUX)
   return output;
 }