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

content/browser/webui/web_ui.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 "content/browser/webui/web_ui.h"
 
 #include "base/i18n/rtl.h"
 #include "base/json/json_writer.h"
 #include "base/stl_util.h"
 #include "base/string_number_conversions.h"
@@ skipping 24 matching lines @@
     parameters += UTF8ToUTF16(json);
   }
   return ASCIIToUTF16(function_name) +
       char16('(') + parameters + char16(')') + char16(';');
 }
 
 WebUI::WebUI(TabContents* contents)
     : hide_favicon_(false),
       focus_location_bar_by_default_(false),
       should_hide_url_(false),
-      link_transition_type_(PageTransition::LINK),
+      link_transition_type_(content::PAGE_TRANSITION_LINK),
       bindings_(content::BINDINGS_POLICY_WEB_UI),
       register_callback_overwrites_(false),
       tab_contents_(contents) {
   DCHECK(contents);
   GenericHandler* handler = new GenericHandler();
   AddMessageHandler(handler->Attach(this));
 }
 
 WebUI::~WebUI() {
   // TODO(csilv): Remove legacy callback support.
@@ skipping 215 matching lines @@
   return false;
 }
 
 string16 WebUIMessageHandler::ExtractStringValue(const ListValue* value) {
   string16 string16_value;
   if (value->GetString(0, &string16_value))
     return string16_value;
   NOTREACHED();
   return string16();
 }