Stop using an atom to store plugin name/version on Windows.

content/common/plugin_constants_win.cc

Index: content/common/plugin_constants_win.cc
diff --git a/content/common/plugin_constants_win.cc b/content/common/plugin_constants_win.cc
index edaeffd6b2e1d052353c7f6c9dfeb6296b5a81ca..026885677e2db5ed71161c513946fcfb1961f5cb 100644
--- a/content/common/plugin_constants_win.cc
+++ b/content/common/plugin_constants_win.cc
@@ -9,8 +9,6 @@ namespace content {
 const base::char16 kNativeWindowClassName[] = L"NativeWindowClass";
 const base::char16 kWrapperNativeWindowClassName[] =
     L"WrapperNativeWindowClass";
-const base::char16 kPluginNameAtomProperty[] = L"PluginNameAtom";
-const base::char16 kPluginVersionAtomProperty[] = L"PluginVersionAtom";
 const base::char16 kDummyActivationWindowName[] = L"DummyWindowForActivation";
 const base::char16 kPaintMessageName[] = L"Chrome_CustomPaintil";
 const base::char16 kRegistryMozillaPlugins[] = L"SOFTWARE\\MozillaPlugins";