Browser Plugin: Implement CanGoBack/CanGoForward

content/renderer/browser_plugin/browser_plugin_bindings.cc

Index: content/renderer/browser_plugin/browser_plugin_bindings.cc
diff --git a/content/renderer/browser_plugin/browser_plugin_bindings.cc b/content/renderer/browser_plugin/browser_plugin_bindings.cc
index 56230a5f84c9e7f7ef3bf6cb3b953080c147fae1..afb0556a27f35540af3215421dd71dc304f61857 100644
--- a/content/renderer/browser_plugin/browser_plugin_bindings.cc
+++ b/content/renderer/browser_plugin/browser_plugin_bindings.cc
@@ -39,6 +39,8 @@ namespace {
 
 const char kAddEventListener[] = "addEventListener";
 const char kBackMethod[] = "back";
+const char kCanGoBack[] = "canGoBack";
+const char kCanGoForward[] = "canGoForward";
 const char kForwardMethod[] = "forward";
 const char kGetProcessId[] = "getProcessId";
 const char kGoMethod[] = "go";
@@ -62,6 +64,14 @@ bool IdentifierIsBackMethod(NPIdentifier identifier) {
   return WebBindings::getStringIdentifier(kBackMethod) == identifier;
 }
 
+bool IdentifierIsCanGoBack(NPIdentifier identifier) {
+  return WebBindings::getStringIdentifier(kCanGoBack) == identifier;
+}
+
+bool IdentifierIsCanGoForward(NPIdentifier identifier) {
+  return WebBindings::getStringIdentifier(kCanGoForward) == identifier;
+}
+
 bool IdentifierIsForwardMethod(NPIdentifier identifier) {
   return WebBindings::getStringIdentifier(kForwardMethod) == identifier;
 }
@@ -151,6 +161,12 @@ bool BrowserPluginBindingsHasMethod(NPObject* np_obj, NPIdentifier name) {
   if (IdentifierIsBackMethod(name))
     return true;
 
+  if (IdentifierIsCanGoBack(name))
+    return true;
+
+  if (IdentifierIsCanGoForward(name))
+    return true;
+
   if (IdentifierIsForwardMethod(name))
     return true;
 
@@ -207,6 +223,18 @@ bool BrowserPluginBindingsInvoke(NPObject* np_obj, NPIdentifier name,
     return true;
   }
 
+  if (IdentifierIsCanGoBack(name) && !arg_count) {
+    result->type = NPVariantType_Bool;
+    result->value.boolValue = bindings->instance()->CanGoBack();
+    return true;
+  }
+
+  if (IdentifierIsCanGoForward(name) && !arg_count) {
+    result->type = NPVariantType_Bool;
+    result->value.boolValue = bindings->instance()->CanGoForward();
+    return true;
+  }
+
   if (IdentifierIsForwardMethod(name) && !arg_count) {
     bindings->instance()->Forward();
     return true;