RefCounted types should not have public destructors, Linux fixes

chrome/renderer/pepper/ppb_pdf_impl.cc

Index: chrome/renderer/pepper/ppb_pdf_impl.cc
diff --git a/chrome/renderer/pepper/ppb_pdf_impl.cc b/chrome/renderer/pepper/ppb_pdf_impl.cc
index f99f4ff3efabbb3b38bfc199060abbcd834f89ee..ff3baea367f5f7f75acb7817df245cd935b93bd7 100644
--- a/chrome/renderer/pepper/ppb_pdf_impl.cc
+++ b/chrome/renderer/pepper/ppb_pdf_impl.cc
@@ -50,8 +50,6 @@ class PrivateFontFile : public ppapi::Resource {
       : Resource(ppapi::OBJECT_IS_IMPL, instance),
         fd_(fd) {
   }
-  virtual ~PrivateFontFile() {
-  }
 
   bool GetFontTable(uint32_t table,
                     void* output,
@@ -63,6 +61,9 @@ class PrivateFontFile : public ppapi::Resource {
     return rv;
   }
 
+ protected:
+  virtual ~PrivateFontFile() {}
+
  private:
   int fd_;
 };