Move PageTransition into content namespace. While I'm touching all these files, I've also updated...

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

 // Copyright (c) 2011 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 "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/extensions/extension_install_dialog.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 281 matching lines @@
 }
 
 views::View* ExtensionInstallDialogView::GetContentsView() {
   return this;
 }
 
 void ExtensionInstallDialogView::LinkClicked(views::Link* source,
                                              int event_flags) {
   GURL store_url(
       extension_urls::GetWebstoreItemDetailURLPrefix() + extension_->id());
-  BrowserList::GetLastActive()->
-      OpenURL(store_url, GURL(), NEW_FOREGROUND_TAB, PageTransition::LINK);
+  BrowserList::GetLastActive()->OpenURL(
+      store_url, GURL(), NEW_FOREGROUND_TAB, content::PAGE_TRANSITION_LINK);
   GetWidget()->Close();
 }
 
 void ShowExtensionInstallDialog(
     Profile* profile,
     ExtensionInstallUI::Delegate* delegate,
     const Extension* extension,
     SkBitmap* icon,
     const ExtensionInstallUI::Prompt& prompt) {
 #if defined(OS_CHROMEOS)
@@ skipping 14 matching lines @@
   }
 
   ExtensionInstallDialogView* dialog = new ExtensionInstallDialogView(
       delegate, extension, icon, prompt);
 
   views::Widget* window =  browser::CreateViewsWindow(
       browser_window->GetNativeHandle(), dialog);
 
   window->Show();
 }