Generate param traits size methods for IPC files in content/ (and traits it depends on).

content/common/media/media_param_traits.h

Index: content/common/media/media_param_traits.h
diff --git a/content/common/media/media_param_traits.h b/content/common/media/media_param_traits.h
index 70675edba3e9df531ca7f78d8c5b2ee51f311e0d..28d3647281d05e1b07e4677270cb0a5edcc78e0a 100644
--- a/content/common/media/media_param_traits.h
+++ b/content/common/media/media_param_traits.h
@@ -19,6 +19,7 @@ namespace IPC {
 template <>
 struct CONTENT_EXPORT ParamTraits<media::AudioParameters> {
   typedef media::AudioParameters param_type;
+  static void GetSize(base::PickleSizer* s, const param_type& p);
   static void Write(base::Pickle* m, const param_type& p);
   static bool Read(const base::Pickle* m,
                    base::PickleIterator* iter,
@@ -29,6 +30,7 @@ struct CONTENT_EXPORT ParamTraits<media::AudioParameters> {
 template <>
 struct CONTENT_EXPORT ParamTraits<media::VideoCaptureFormat> {
   typedef media::VideoCaptureFormat param_type;
+  static void GetSize(base::PickleSizer* s, const param_type& p);
   static void Write(base::Pickle* m, const param_type& p);
   static bool Read(const base::Pickle* m,
                    base::PickleIterator* iter,