Contributed by Eriq Augustine <eriq.augustine@gmail.com>

chrome/browser/extensions/extension_menu_manager.cc

Index: chrome/browser/extensions/extension_menu_manager.cc
===================================================================
--- chrome/browser/extensions/extension_menu_manager.cc	(revision 114114)
+++ chrome/browser/extensions/extension_menu_manager.cc	(working copy)
@@ -461,6 +461,58 @@
   }
 }
 
+void ExtensionMenuManager::SanitizeRadioButtons() {

[Aaron Boodman, 2011/12/15 00:53:55]

You could pass in the extension ID to cut down on the work being done here.

+  MenuItemMap::iterator i;
+  for (i = context_items_.begin(); i != context_items_.end(); ++i) {
+    RecursiveSanitizeRadioButtons(i->second);
+  }
+}
+
+void ExtensionMenuManager::RecursiveSanitizeRadioButtons(
+    const ExtensionMenuItem::List& item_list) {
+  ExtensionMenuItem::List::const_iterator i;
+
+  i = item_list.begin();
+  while (i != item_list.end()) {
+    if ((*i)->child_count() > 0) {
+      RecursiveSanitizeRadioButtons((*i)->children());
+    }
+
+    if ((*i)->type() == ExtensionMenuItem::RADIO) {
+      ExtensionMenuItem::List::const_iterator radio_run_ittr;

[Aaron Boodman, 2011/12/15 00:53:55]

s/ittr/iter/g ?

[Aaron Boodman, 2011/12/15 00:53:55]

Better to declare this right about the loop where it is used for clarity.

+
+      // If there are multiple items selected, the last one will override the
+      // others. This is the default behavior when adding radio items via
+      // chrome.contextMenus.create().
+      ExtensionMenuItem::List::const_iterator last_checked = item_list.end();
+      for (radio_run_ittr = i; radio_run_ittr != item_list.end();
+          ++radio_run_ittr) {
+        if ((*radio_run_ittr)->type() != ExtensionMenuItem::RADIO) {
+          break;
+        }
+
+        if ((*radio_run_ittr)->checked()) {
+          last_checked = radio_run_ittr;
+        }
+
+        (*radio_run_ittr)->SetChecked(false);
+      }
+
+      // If check radio items were found in this run,
+      // check the first radio item in the list (i).
+      if (last_checked != item_list.end()) {
+        (*last_checked)->SetChecked(true);
+      } else {
+        (*i)->SetChecked(true);
+      }
+
+      i = radio_run_ittr;
+    } else {
+      ++i;
+    }
+  }
+}
+
 const SkBitmap& ExtensionMenuManager::GetIconForExtension(
     const std::string& extension_id) {
   return icon_manager_.GetIcon(extension_id);