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

components/printing/common/print_messages.cc

Index: components/printing/common/print_messages.cc
diff --git a/components/printing/common/print_messages.cc b/components/printing/common/print_messages.cc
index ce1b8d5349210064b0049d0811053db7a0a16b29..11dc6dbc410310b3a3c597495e2d5b4d5bff1ca4 100644
--- a/components/printing/common/print_messages.cc
+++ b/components/printing/common/print_messages.cc
@@ -60,6 +60,9 @@ PrintMsg_Print_Params::PrintMsg_Print_Params()
     should_print_backgrounds(false) {
 }
 
+PrintMsg_Print_Params::PrintMsg_Print_Params(
+    const PrintMsg_Print_Params& other) = default;
+
 PrintMsg_Print_Params::~PrintMsg_Print_Params() {}
 
 void PrintMsg_Print_Params::Reset() {
@@ -88,6 +91,9 @@ PrintMsg_PrintPages_Params::PrintMsg_PrintPages_Params()
   : pages() {
 }
 
+PrintMsg_PrintPages_Params::PrintMsg_PrintPages_Params(
+    const PrintMsg_PrintPages_Params& other) = default;
+
 PrintMsg_PrintPages_Params::~PrintMsg_PrintPages_Params() {}
 
 void PrintMsg_PrintPages_Params::Reset() {