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

media/gpu/ipc/common/media_messages.cc

Index: media/gpu/ipc/common/media_messages.cc
diff --git a/media/gpu/ipc/common/media_messages.cc b/media/gpu/ipc/common/media_messages.cc
index d1916f32a1cb47f54f71ec611bd7adc32929ab91..0c3c6f7adbaaa9451141804b2c9c93cd3f199726 100644
--- a/media/gpu/ipc/common/media_messages.cc
+++ b/media/gpu/ipc/common/media_messages.cc
@@ -12,6 +12,20 @@
 
 namespace IPC {
 
+void ParamTraits<media::BitstreamBuffer>::GetSize(base::PickleSizer* s,
+                                                  const param_type& p) {
+  GetParamSize(s, p.id());
+  GetParamSize(s, static_cast<uint64_t>(p.size()));
+  GetParamSize(s, static_cast<uint64_t>(p.offset()));
+  GetParamSize(s, p.presentation_timestamp());
+  GetParamSize(s, p.key_id());
+  if (!p.key_id().empty()) {
+    GetParamSize(s, p.iv());
+    GetParamSize(s, p.subsamples());
+  }
+  GetParamSize(s, p.handle());
+}
+
 void ParamTraits<media::BitstreamBuffer>::Write(base::Pickle* m,
                                                 const param_type& p) {
   WriteParam(m, p.id());