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

url/ipc/url_param_traits.cc

Index: url/ipc/url_param_traits.cc
diff --git a/url/ipc/url_param_traits.cc b/url/ipc/url_param_traits.cc
index e40ae8f9a3c9ccc4558cf6fb559f0342ebec545d..b41e4716204f9a383e5cb64980fdbf86a2633a9e 100644
--- a/url/ipc/url_param_traits.cc
+++ b/url/ipc/url_param_traits.cc
@@ -8,6 +8,15 @@
 
 namespace IPC {
 
+void ParamTraits<GURL>::GetSize(base::PickleSizer* s, const GURL& p) {
+  if (p.possibly_invalid_spec().length() > url::kMaxURLChars || !p.is_valid()) {
+    GetParamSize(s, std::string());
+    return;
+  }
+
+  GetParamSize(s, p.possibly_invalid_spec());
+}
+
 void ParamTraits<GURL>::Write(base::Pickle* m, const GURL& p) {
   if (p.possibly_invalid_spec().length() > url::kMaxURLChars) {
     m->WriteString(std::string());