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

chrome/browser/pdf_unsupported_feature.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 "chrome/browser/pdf_unsupported_feature.h"
 
 #include "base/bind.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "base/version.h"
@@ skipping 111 matching lines @@
       false, ASCIIToUTF16(chrome::ChromeContentClient::kPDFPluginName));
 }
 
 void PDFEnableAdobeReaderInfoBarDelegate::OnNo() {
   UserMetrics::RecordAction(UserMetricsAction("PDF_EnableReaderInfoBarCancel"));
 }
 
 // Launch the url to get the latest Adbobe Reader installer.
 void OpenReaderUpdateURL(TabContents* tab) {
   tab->OpenURL(GURL(kReaderUpdateUrl), GURL(), CURRENT_TAB,
-               PageTransition::LINK);
+               content::PAGE_TRANSITION_LINK);
 }
 
 // Opens the PDF using Adobe Reader.
 void OpenUsingReader(TabContentsWrapper* tab,
                      const WebPluginInfo& reader_plugin,
                      InfoBarDelegate* old_delegate,
                      InfoBarDelegate* new_delegate) {
   ChromePluginServiceFilter::GetInstance()->OverridePluginForTab(
       tab->render_view_host()->process()->id(),
       tab->render_view_host()->routing_id(),
@@ skipping 257 matching lines @@
   // Only works for Windows for now.  For Mac, we'll have to launch the file
   // externally since Adobe Reader doesn't work inside Chrome.
   return;
 #endif
 
   PluginService::GetInstance()->GetPluginGroups(
       base::Bind(&GotPluginGroupsCallback,
           tab->render_view_host()->process()->id(),
           tab->render_view_host()->routing_id()));
 }