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

chrome/browser/ui/gtk/tabs/tab_strip_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.
 
 #include "chrome/browser/ui/gtk/tabs/tab_strip_gtk.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/i18n/rtl.h"
@@ skipping 1748 matching lines @@
         &match, NULL);
     url = match.destination_url;
   } else {
     std::string url_string(reinterpret_cast<char*>(data));
     url = GURL(url_string.substr(0, url_string.find_first_of('\n')));
   }
   if (!url.is_valid())
     return false;
 
   browser::NavigateParams params(window()->browser(), url,
-                                 PageTransition::LINK);
+                                 content::PAGE_TRANSITION_LINK);
   params.tabstrip_index = drop_index;
 
   if (drop_before) {
     params.disposition = NEW_FOREGROUND_TAB;
   } else {
     params.disposition = CURRENT_TAB;
     params.source_contents = model_->GetTabContentsAt(drop_index);
   }
 
   browser::Navigate(&params);
@@ skipping 350 matching lines @@
       break;
     case 2: {
       // On middle-click, try to parse the PRIMARY selection as a URL and load
       // it instead of creating a blank page.
       GURL url;
       if (!gtk_util::URLFromPrimarySelection(model_->profile(), &url))
         return;
 
       Browser* browser = window_->browser();
       DCHECK(browser);
-      browser->AddSelectedTabWithURL(url, PageTransition::TYPED);
+      browser->AddSelectedTabWithURL(url, content::PAGE_TRANSITION_TYPED);
       break;
     }
     default:
       NOTREACHED() << "Got click on new tab button with unhandled mouse "
                    << "button " << mouse_button;
   }
 }
 
 void TabStripGtk::SetTabBounds(TabGtk* tab, const gfx::Rect& bounds) {
   gfx::Rect bds = bounds;
@@ skipping 35 matching lines @@
 
   // Let the middle mouse button initiate clicks as well.
   gtk_util::SetButtonTriggersNavigation(button->widget());
   g_signal_connect(button->widget(), "clicked",
                    G_CALLBACK(OnNewTabClickedThunk), this);
   gtk_widget_set_can_focus(button->widget(), FALSE);
   gtk_fixed_put(GTK_FIXED(tabstrip_.get()), button->widget(), 0, 0);
 
   return button;
 }