Made the revoke buttons in the App Info dialog tab-navigable

chrome/browser/ui/views/apps/app_info_dialog/app_info_permissions_panel.cc

Index: chrome/browser/ui/views/apps/app_info_dialog/app_info_permissions_panel.cc
diff --git a/chrome/browser/ui/views/apps/app_info_dialog/app_info_permissions_panel.cc b/chrome/browser/ui/views/apps/app_info_dialog/app_info_permissions_panel.cc
index fdfb8109759643bb82de56851251e5dc8b34a108..37f8118eb829ca0939a1067085dc390e2454beff 100644
--- a/chrome/browser/ui/views/apps/app_info_dialog/app_info_permissions_panel.cc
+++ b/chrome/browser/ui/views/apps/app_info_dialog/app_info_permissions_panel.cc
@@ -54,6 +54,12 @@ class RevokeButton : public views::ImageButton, public views::ButtonListener {
              rb.GetImageNamed(IDR_DISABLE_P).ToImageSkia());
     SetBorder(scoped_ptr<views::Border>());
     SetSize(GetPreferredSize());
+
+    // Make the button focusable & give it alt-text so permissions can be
+    // revoked using only the keyboard.
+    SetFocusable(true);
+    SetTooltipText(l10n_util::GetStringUTF16(
+        IDS_APPLICATION_INFO_REVOKE_PERMISSION_ALT_TEXT));
   }
   virtual ~RevokeButton() {}