Make members of Singleton<T> private and only visible to the singleton type.

printing/printed_document.cc

Index: printing/printed_document.cc
diff --git a/printing/printed_document.cc b/printing/printed_document.cc
index 75d4b952581258fac5d2fb43d51dd71d0c7c2d1a..0880da585aaed415afd302d14a9a2a03f696093b 100644
--- a/printing/printed_document.cc
+++ b/printing/printed_document.cc
@@ -13,8 +13,8 @@
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/i18n/file_util_icu.h"
+#include "base/lazy_instance.h"
 #include "base/message_loop.h"
-#include "base/singleton.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "base/i18n/time_formatting.h"
@@ -37,7 +37,8 @@ struct PrintDebugDumpPath {
   FilePath debug_dump_path;
 };
 
-Singleton<PrintDebugDumpPath> g_debug_dump_info;
+static base::LazyInstance<PrintDebugDumpPath> g_debug_dump_info(
+    base::LINKER_INITIALIZED);
 
 }  // namespace
 
@@ -244,7 +245,7 @@ void PrintedDocument::PrintHeaderFooter(gfx::NativeDrawingContext context,
 }
 
 void PrintedDocument::DebugDump(const PrintedPage& page) {
-  if (!g_debug_dump_info->enabled)
+  if (!g_debug_dump_info.Get().enabled)
     return;
 
   string16 filename;
@@ -258,19 +259,19 @@ void PrintedDocument::DebugDump(const PrintedPage& page) {
   filename += ASCIIToUTF16("_.emf");
 #if defined(OS_WIN)
   page.native_metafile()->SaveTo(
-      g_debug_dump_info->debug_dump_path.Append(filename).ToWStringHack());
+      g_debug_dump_info.Get().debug_dump_path.Append(filename).ToWStringHack());
 #else  // OS_WIN
   NOTIMPLEMENTED();
 #endif  // OS_WIN
 }
 
 void PrintedDocument::set_debug_dump_path(const FilePath& debug_dump_path) {
-  g_debug_dump_info->enabled = !debug_dump_path.empty();
-  g_debug_dump_info->debug_dump_path = debug_dump_path;
+  g_debug_dump_info.Get().enabled = !debug_dump_path.empty();
+  g_debug_dump_info.Get().debug_dump_path = debug_dump_path;
 }
 
 const FilePath& PrintedDocument::debug_dump_path() {
-  return g_debug_dump_info->debug_dump_path;
+  return g_debug_dump_info.Get().debug_dump_path;
 }
 
 PrintedDocument::Mutable::Mutable(PrintedPagesSource* source)