components: Add out-of-line copy ctors for complex classes.

components/nacl/common/pnacl_types.h

Index: components/nacl/common/pnacl_types.h
diff --git a/components/nacl/common/pnacl_types.h b/components/nacl/common/pnacl_types.h
index fdebd58a45fc9a73cadd45d1ae6905349b7bc571..eb7e1742020b6d3517248ba3a989a9ec3d1e2218 100644
--- a/components/nacl/common/pnacl_types.h
+++ b/components/nacl/common/pnacl_types.h
@@ -20,6 +20,7 @@ namespace nacl {
 // nacl_host_messages.h.
 struct PnaclCacheInfo {
   PnaclCacheInfo();
+  PnaclCacheInfo(const PnaclCacheInfo& other);
   ~PnaclCacheInfo();
   GURL pexe_url;
   int abi_version;