Track the active ExtensionKeybindingRegistry and make it available to EventRewriter.

chrome/browser/ui/views/toolbar/toolbar_view.cc

Index: chrome/browser/ui/views/toolbar/toolbar_view.cc
diff --git a/chrome/browser/ui/views/toolbar/toolbar_view.cc b/chrome/browser/ui/views/toolbar/toolbar_view.cc
index 573795fccd7857eeda603eeecd07b73870235446..5dbda94c696865b802e2b9e7d1467471f0dc7eba 100644
--- a/chrome/browser/ui/views/toolbar/toolbar_view.cc
+++ b/chrome/browser/ui/views/toolbar/toolbar_view.cc
@@ -14,6 +14,7 @@
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/command_updater.h"
+#include "chrome/browser/extensions/extension_commands_global_registry.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/themes/theme_service.h"
@@ -271,8 +272,12 @@ void ToolbarView::Init() {
 void ToolbarView::OnWidgetVisibilityChanged(views::Widget* widget,
                                             bool visible) {
   // Safe to call multiple times; the bubble will only appear once.
-  if (visible)
+  if (visible) {
     extension_message_bubble_factory_->MaybeShow(app_menu_);
+    extensions::ExtensionCommandsGlobalRegistry::Get(browser_->profile())

[Devlin, 2014/09/11 21:38:13]

We also need to unset this, either in ToolbarView or BrowserActionsContainer,
when the BrowserActionsContainer gets destroyed.  It would probably make the
most sense to do in a OnWidgetDestroyed() method.

[Devlin, 2014/09/11 21:40:00]

And also when activation is lost, and not necessarily sent to another window
with a toolbar (like, e.g., an app window).  So also just an else clause to this
part.

[David Tseng, 2014/09/11 23:57:09]

That's what I considered originally...but are we guaranteed this widget looses
visibility before the new widget gains/is notified of its visibility change?

[David Tseng, 2014/09/11 23:57:09]

Yeah, I wasn't sure about this one. Will add to OnWidgetDestroyed.

[Devlin, 2014/09/12 00:10:33]

Sky knows best here, so I definitely defer to him. :)  But a cursory look
through the code implied that no, we won't get a visibility change prior to a
deletion (so we need OnWidgetDestroyed()).

+        ->set_active_registry(
+            browser_actions_->extension_keybinding_registry());
+  }
 }
 
 void ToolbarView::Update(WebContents* tab) {