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

content/common/content_param_traits.cc

Index: content/common/content_param_traits.cc
diff --git a/content/common/content_param_traits.cc b/content/common/content_param_traits.cc
index 07e1a239bfd4ddd19b0b3a6f5ce221ee27132af9..7b441c3f1c0efc63f684452737c037282b54f4d7 100644
--- a/content/common/content_param_traits.cc
+++ b/content/common/content_param_traits.cc
@@ -12,6 +12,11 @@
 
 namespace IPC {
 
+void ParamTraits<WebInputEventPointer>::GetSize(base::PickleSizer* s,
+                                                const param_type& p) {
+  s->AddData(p->size);
+}
+
 void ParamTraits<WebInputEventPointer>::Write(base::Pickle* m,
                                               const param_type& p) {
   m->WriteData(reinterpret_cast<const char*>(p), p->size);
@@ -59,6 +64,13 @@ void ParamTraits<WebInputEventPointer>::Log(const param_type& p,
 
 }  // namespace IPC
 
+// Generate param traits size methods.
+#include "ipc/param_traits_size_macros.h"
+namespace IPC {
+#undef CONTENT_COMMON_CONTENT_PARAM_TRAITS_MACROS_H_
+#include "content/common/content_param_traits_macros.h"
+}
+
 // Generate param traits write methods.
 #include "ipc/param_traits_write_macros.h"
 namespace IPC {