Use console.log to report NaCl errors in Chrome instead of alerts

src/trusted/plugin/npapi/browser_impl_npapi.h

Index: src/trusted/plugin/npapi/browser_impl_npapi.h
===================================================================
--- src/trusted/plugin/npapi/browser_impl_npapi.h	(revision 3042)
+++ src/trusted/plugin/npapi/browser_impl_npapi.h	(working copy)
@@ -43,9 +43,14 @@
                      const nacl::string& text);
 
   // Evaluate a JavaScript string in the browser.
-  virtual bool EvalString(InstanceIdentifier plugin_identifier,
+  virtual bool EvalString(InstanceIdentifier instance_id,
                           const nacl::string& handler_string);
 
+  // Write to the JavaScript console. Currently works in Chrome only, generates
+  // an alert in other browsers.
+  virtual bool AddToConsole(InstanceIdentifier instance_id,
+                            const nacl::string& text);
+
   // Gets the full URL of the current page.
   bool GetFullURL(InstanceIdentifier instance_id,
                   nacl::string* full_url);