Browser Plugin: Implement CanGoBack/CanGoForward

content/test/data/browser_plugin_embedder.html

Index: content/test/data/browser_plugin_embedder.html
diff --git a/content/test/data/browser_plugin_embedder.html b/content/test/data/browser_plugin_embedder.html
index 45b374e3ac9f9d91494114f5cfb0b6418c9a0168..e192865d642cff04036c1a84c1e3e849e04cb307 100644
--- a/content/test/data/browser_plugin_embedder.html
+++ b/content/test/data/browser_plugin_embedder.html
@@ -27,6 +27,14 @@ function Back() {
   var plugin = document.getElementById('plugin');
   plugin.back();
 }
+function CanGoBack() {
+  var plugin = document.getElementById('plugin');
+  return plugin.canGoBack();
+}
+function CanGoForward() {
+  var plugin = document.getElementById('plugin');
+  return plugin.canGoForward();
+}
 function Forward() {
   var plugin = document.getElementById('plugin');
   plugin.forward();