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

components/page_load_metrics/common/page_load_metrics_messages.cc

Index: components/page_load_metrics/common/page_load_metrics_messages.cc
diff --git a/components/page_load_metrics/common/page_load_metrics_messages.cc b/components/page_load_metrics/common/page_load_metrics_messages.cc
index a7990e70a9eb5681c6465f0397b3f463ded22df1..07bdd98ff65ed49c2739823d58eda706812d0ce9 100644
--- a/components/page_load_metrics/common/page_load_metrics_messages.cc
+++ b/components/page_load_metrics/common/page_load_metrics_messages.cc
@@ -14,6 +14,12 @@
 #include "ipc/struct_destructor_macros.h"
 #include "components/page_load_metrics/common/page_load_metrics_messages.h"
 
+// Generate param traits size methods.
+#include "ipc/param_traits_size_macros.h"
+namespace IPC {
+#include "components/page_load_metrics/common/page_load_metrics_messages.h"
+}
+
 // Generate param traits write methods.
 #include "ipc/param_traits_write_macros.h"
 namespace IPC {