Ensure default dialog button focus remains after a dialog update.

chrome/browser/ui/views/extensions/extension_install_dialog_view.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_install_dialog_view.h"
 
 #include <stddef.h>
 #include <algorithm>
 #include <string>
 #include <utility>
@@ skipping 609 matching lines @@
     timer_.Start(FROM_HERE,
                  base::TimeDelta::FromMilliseconds(g_install_delay_in_ms),
                  base::Bind(&ExtensionInstallDialogView::EnableInstallButton,
                             base::Unretained(this)));
   }
 }
 
 void ExtensionInstallDialogView::EnableInstallButton() {
   install_button_enabled_ = true;
   GetDialogClientView()->UpdateDialogButtons();
+  GetInitiallyFocusedView()->RequestFocus();
 }
 
 void ExtensionInstallDialogView::UpdateInstallResultHistogram(bool accepted)
     const {
   if (prompt_->type() == ExtensionInstallPrompt::INSTALL_PROMPT)
     UMA_HISTOGRAM_BOOLEAN("Extensions.InstallPrompt.Accepted", accepted);
 }
 
 // ExpandableContainerView::DetailsView ----------------------------------------
 
@@ skipping 150 matching lines @@
   gfx::ImageSkia icon = gfx::CreateVectorIcon(
       expanded ? kCaretUpIcon : kCaretDownIcon, gfx::kChromeIconGrey);
   arrow_toggle_->SetImage(views::Button::STATE_NORMAL, &icon);
 }
 
 // static
 ExtensionInstallPrompt::ShowDialogCallback
 ExtensionInstallPrompt::GetViewsShowDialogCallback() {
   return base::Bind(&ShowExtensionInstallDialogImpl);
 }