Deprecate file_util::AppendToPath() on non-Windows.

chrome/plugin/chrome_plugin_host.cc

Index: chrome/plugin/chrome_plugin_host.cc
diff --git a/chrome/plugin/chrome_plugin_host.cc b/chrome/plugin/chrome_plugin_host.cc
index ab459f4d8d6971829792f715cb5d9f76f4960d28..4561cc4f3933085d705bbe8ab99abb5f3e108185 100644
--- a/chrome/plugin/chrome_plugin_host.cc
+++ b/chrome/plugin/chrome_plugin_host.cc
@@ -422,11 +422,13 @@ int STDCALL CPB_GetBrowsingContextInfo(
     if (buf_size < sizeof(char*))
       return sizeof(char*);
 
-    std::wstring wretval = CommandLine::ForCurrentProcess()->
-        GetSwitchValue(switches::kPluginDataDir);
-    DCHECK(!wretval.empty());
-    file_util::AppendToPath(&wretval, chrome::kChromePluginDataDirname);
-    *static_cast<char**>(buf) = CPB_StringDup(CPB_Alloc, WideToUTF8(wretval));
+    FilePath path = CommandLine::ForCurrentProcess()->
+                    GetSwitchValuePath(switches::kPluginDataDir);
+    DCHECK(!path.empty());
+    std::string retval = WideToUTF8(
+        path.Append(chrome::kChromePluginDataDirname).ToWStringHack());
+    *static_cast<char**>(buf) = CPB_StringDup(CPB_Alloc, retval);
+
     return CPERR_SUCCESS;
     }
   case CPBROWSINGCONTEXT_UI_LOCALE_PTR: {