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

content/content_common.gypi

 # 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.
 
 {
   'dependencies': [
     '../base/base.gyp:base',
     '../build/temp_gyp/googleurl.gyp:googleurl',
     '../gpu/gpu.gyp:gpu_ipc',
     '../ipc/ipc.gyp:ipc',
@@ skipping 11 matching lines @@
     '../webkit/support/webkit_support.gyp:fileapi',
   ],
   'include_dirs': [
     '..',
   ],
   'export_dependent_settings': [
     '../base/base.gyp:base',
   ],
   'sources': [
     'public/common/bindings_policy.h',
+    'public/common/page_transition_types.cc',
+    'public/common/page_transition_types.h',
     'public/common/resource_dispatcher_delegate.h',
     'public/common/view_types.h',
     'common/appcache/appcache_backend_proxy.cc',
     'common/appcache/appcache_backend_proxy.h',
     'common/appcache/appcache_dispatcher.cc',
     'common/appcache/appcache_dispatcher.h',
     'common/appcache_messages.h',
     'common/child_process.cc',
     'common/child_process.h',
     'common/child_process_host.cc',
@@ skipping 133 matching lines @@
     'common/np_channel_base.h',
     'common/npobject_base.h',
     'common/npobject_proxy.cc',
     'common/npobject_proxy.h',
     'common/npobject_stub.cc',
     'common/npobject_stub.h',
     'common/npobject_util.cc',
     'common/npobject_util.h',
     'common/p2p_messages.h',
     'common/p2p_sockets.h',
-    'common/page_transition_types.cc',
-    'common/page_transition_types.h',
     'common/page_type.h',
     'common/page_zoom.h',
     'common/pepper_file_messages.cc',
     'common/pepper_file_messages.h',
     'common/pepper_messages.cc',
     'common/pepper_messages.h',
     'common/pepper_plugin_registry.cc',
     'common/pepper_plugin_registry.h',
     'common/plugin_carbon_interpose_constants_mac.cc',
     'common/plugin_carbon_interpose_constants_mac.h',
@@ skipping 138 matching lines @@
       ],
       'link_settings': {
         'libraries': [
           '-lEGL',
           '-lGLESv2',
         ],
       },
     }],
   ],
 }