Take 2 at implementing activeTab.

chrome/browser/extensions/extension_toolbar_model.cc

Index: chrome/browser/extensions/extension_toolbar_model.cc
diff --git a/chrome/browser/extensions/extension_toolbar_model.cc b/chrome/browser/extensions/extension_toolbar_model.cc
index aeea4faee9756221df897076b99f00ebcd8f0c07..6a36fe592e19aa00cbd4895d7bdbfa075bad2add 100644
--- a/chrome/browser/extensions/extension_toolbar_model.cc
+++ b/chrome/browser/extensions/extension_toolbar_model.cc
@@ -7,6 +7,7 @@
 #include "chrome/browser/extensions/extension_browser_event_router.h"
 #include "chrome/browser/extensions/extension_prefs.h"
 #include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
@@ -95,6 +96,9 @@ ExtensionToolbarModel::Action ExtensionToolbarModel::ExecuteBrowserAction(
   if (tab_id < 0)
     return ACTION_NONE;
 
+  tab_contents->extension_tab_helper()->active_tab_permission_manager()->Grant(

[Aaron Boodman, 2012/06/06 01:03:13]

I hate these kind of method names, but it might be worth it here: MaybeGrant?

[not at google - send to devlin, 2012/06/06 07:38:40]

yeah I hate Maybe too. So vague, and always requires looking up the comment on
the method to understand.  Maybe... GrantIfPossible?  GrantIfPermissible
(ewwwww)? GrantIfHasPermission? GrantIfHasActiveTab? 
GrantIfHasActiveTabPermission?

bleh, MaybeGrant it is.

+      extension);
+
   ExtensionAction* browser_action = extension->browser_action();
   if (browser_action->HasPopup(tab_id)) {
     if (popup_url_out)