Show a warning message if the cache might not be cleared between runs.

chrome/renderer/renderer_glue.cc

Index: chrome/renderer/renderer_glue.cc
diff --git a/chrome/renderer/renderer_glue.cc b/chrome/renderer/renderer_glue.cc
index 07301b57f50a9b86545aac3e701967b2fe8ac0c0..72a7629f0537453c9292d54cb291bf3ab4af6962 100644
--- a/chrome/renderer/renderer_glue.cc
+++ b/chrome/renderer/renderer_glue.cc
@@ -15,6 +15,7 @@
 #include "app/clipboard/clipboard.h"
 #include "app/clipboard/scoped_clipboard_writer.h"
 #include "app/resource_bundle.h"
+#include "base/command_line.h"
 #include "base/file_version_info.h"
 #include "base/ref_counted.h"
 #include "base/string_util.h"
@@ -281,4 +282,8 @@ std::string GetProductVersion() {
   return product;
 }
 
+bool IsSingleProcess() {
+  return CommandLine::ForCurrentProcess()->HasSwitch(switches::kSingleProcess);
+}
+
 }  // namespace webkit_glue