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

extensions/common/permissions/api_permission.h

Index: extensions/common/permissions/api_permission.h
diff --git a/extensions/common/permissions/api_permission.h b/extensions/common/permissions/api_permission.h
index a6069dfb0be91b541f2d2dec0862b06adab2c446..47aa543072b8693a8e84c92c163d51de54bfefac 100644
--- a/extensions/common/permissions/api_permission.h
+++ b/extensions/common/permissions/api_permission.h
@@ -323,6 +323,9 @@ class APIPermission {
   virtual APIPermission* Intersect(const APIPermission* rhs) const = 0;
 
   // IPC functions
+  // Gets the size of the data to be written.
+  virtual void GetSize(base::PickleSizer* s) const = 0;
+
   // Writes this into the given IPC message |m|.
   virtual void Write(base::Pickle* m) const = 0;