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

This patch adds out of line copy constructors for classes that our
clang-plugin considers heavy. This is an effort to enable copy
constructor checks by default.

BUG=436357
[email protected], [email protected], [email protected]

Review URL: https://codereview.chromium.org/1728333003

Cr-Commit-Position: refs/heads/master@{#377976}
diff --git a/net/websockets/websocket_extension.h b/net/websockets/websocket_extension.h
index 20f2922..4c42a76 100644
--- a/net/websockets/websocket_extension.h
+++ b/net/websockets/websocket_extension.h
@@ -38,6 +38,7 @@
 
   WebSocketExtension();
   explicit WebSocketExtension(const std::string& name);
+  WebSocketExtension(const WebSocketExtension& other);
   ~WebSocketExtension();
 
   void Add(const Parameter& parameter) { parameters_.push_back(parameter); }