Make sure manifest specified shortcut for Extension Command can not override the built-in shortcuts.

chrome/browser/ui/views/extensions/extension_keybinding_registry_views.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/ui/views/extensions/extension_keybinding_registry_views.h"
 
 #include "chrome/browser/extensions/api/commands/command_service.h"
 #include "chrome/browser/extensions/extension_keybinding_registry.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/views/accelerator_table.h"
 #include "chrome/common/extensions/extension.h"
 #include "ui/views/focus/focus_manager.h"
 
 // static
 void extensions::ExtensionKeybindingRegistry::SetShortcutHandlingSuspended(
     bool suspended) {
   views::FocusManager::set_shortcut_handling_suspended(suspended);
 }
 
+// static
+bool extensions::ExtensionKeybindingRegistry::IsChromeAccelerator(
+    const ui::Accelerator& accelerator) {
+  std::vector<chrome::AcceleratorMapping> accelerators =
+      chrome::GetAcceleratorList();

[sky, 2013/04/09 16:38:01]

This is only applicable to aura and I don't know that it includes the
acclerators used in ash (see ash/accelerators/accelerator_table).

+  for (std::vector<chrome::AcceleratorMapping>::const_iterator it =
+       accelerators.begin(); it != accelerators.end(); ++it) {
+    if (it->keycode == accelerator.key_code() &&
+        it->modifiers == accelerator.modifiers())
+      return true;
+  }
+  return false;
+}
+
 ExtensionKeybindingRegistryViews::ExtensionKeybindingRegistryViews(
     Profile* profile,
     views::FocusManager* focus_manager,
     ExtensionFilter extension_filter,
     Delegate* delegate)
     : ExtensionKeybindingRegistry(profile, extension_filter, delegate),
       profile_(profile),
       focus_manager_(focus_manager) {
   Init();
 }
@@ skipping 63 matching lines @@
   }
 
   CommandExecuted(it->second.first, it->second.second);
 
   return true;
 }
 
 bool ExtensionKeybindingRegistryViews::CanHandleAccelerators() const {
   return true;
 }