Track the active ExtensionKeybindingRegistry and make it available to EventRewriter.

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

Index: chrome/browser/ui/views/toolbar/browser_actions_container.cc
diff --git a/chrome/browser/ui/views/toolbar/browser_actions_container.cc b/chrome/browser/ui/views/toolbar/browser_actions_container.cc
index 5ed94f3e2f00e37eb91ffd966dbf4b2c33d79a12..5bcd62c5801bd805bcf51880fa2bb38284d805d2 100644
--- a/chrome/browser/ui/views/toolbar/browser_actions_container.cc
+++ b/chrome/browser/ui/views/toolbar/browser_actions_container.cc
@@ -1,4 +1,4 @@
-// Copyright 2013 The Chromium Authors. All rights reserved.
+// Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -7,6 +7,7 @@
 #include "base/compiler_specific.h"
 #include "base/stl_util.h"
 #include "chrome/browser/extensions/extension_action_manager.h"
+#include "chrome/browser/extensions/extension_keybinding_registry_tracker.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/extensions/extension_view_host.h"
 #include "chrome/browser/extensions/tab_helper.h"
@@ -953,6 +954,10 @@ void BrowserActionsContainer::OnBrowserActionVisibilityChanged() {
     owner_view_->Layout();
     owner_view_->SchedulePaint();
   }
+
+  if (GetWidget()->IsActive())

[Devlin, 2014/09/11 18:41:01]

This is probably not the best point for this.  This method is called when a
BrowserAction's visibility (might have) changed, but there's no guarantee that
when a window changes, a browser action will become visible/invisible.  I think
a better solution is to listen for when the widget becomes active/inactive.  If
you wanted to rely on ToolbarView (which is already a WidgetObserver) to do
that, I'd say it's fine (but I'll leave that up to sky@).

[David Tseng, 2014/09/11 19:34:20]

Done. (sky@ feel free to suggest alternatives).

+    extensions::ExtensionKeybindingRegistryTracker::Get(profile())
+        ->Update(extension_keybinding_registry_.get());
 }
 
 int BrowserActionsContainer::GetPreferredWidth() {