Move RemoveChars, ReplaceChars, TrimString, and TruncateUTF8ToByteSize to base namespace.

content/browser/browser_plugin/browser_plugin_guest.cc

Index: content/browser/browser_plugin/browser_plugin_guest.cc
diff --git a/content/browser/browser_plugin/browser_plugin_guest.cc b/content/browser/browser_plugin/browser_plugin_guest.cc
index 6d28a5e544fe2a96b31cc5853148d4cf359bcf83..9311ab398720163e1af34388b2dbefb5495650a4 100644
--- a/content/browser/browser_plugin/browser_plugin_guest.cc
+++ b/content/browser/browser_plugin/browser_plugin_guest.cc
@@ -1377,7 +1377,8 @@ void BrowserPluginGuest::OnNavigateGuest(
   if (scheme_is_blocked || !url.is_valid()) {
     if (delegate_) {
       std::string error_type;
-      RemoveChars(net::ErrorToString(net::ERR_ABORTED), "net::", &error_type);
+      base::RemoveChars(net::ErrorToString(net::ERR_ABORTED), "net::",
+                        &error_type);
       delegate_->LoadAbort(true /* is_top_level */, url, error_type);
     }
     return;