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

webkit/tools/test_shell/test_webview_delegate_gtk.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.
 
 // This file was forked off the Mac port.
 
 #include "webkit/tools/test_shell/test_webview_delegate.h"
 
 #include <gtk/gtk.h>
 #include <gdk/gdkx.h>
 
 #include "base/bind.h"
 #include "base/message_loop.h"
 #include "base/utf_string_conversions.h"
 #include "net/base/net_errors.h"
-#include "content/common/page_transition_types.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebCString.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebCursorInfo.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebRect.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebString.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
 #include "ui/gfx/gtk_util.h"
 #include "ui/gfx/point.h"
 #include "webkit/glue/webcursor.h"
 #include "webkit/glue/webdropdata.h"
@@ skipping 236 matching lines @@
 }
 
 void TestWebViewDelegate::SetPageTitle(const string16& title) {
   gtk_window_set_title(GTK_WINDOW(shell_->mainWnd()),
                        ("Test Shell - " + UTF16ToUTF8(title)).c_str());
 }
 
 void TestWebViewDelegate::SetAddressBarURL(const GURL& url) {
   gtk_entry_set_text(GTK_ENTRY(shell_->editWnd()), url.spec().c_str());
 }