components: 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]
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1728033002

Cr-Commit-Position: refs/heads/master@{#377717}
diff --git a/components/query_parser/snippet.cc b/components/query_parser/snippet.cc
index b4840c6..f704409c 100644
--- a/components/query_parser/snippet.cc
+++ b/components/query_parser/snippet.cc
@@ -208,6 +208,8 @@
 Snippet::Snippet() {
 }
 
+Snippet::Snippet(const Snippet& other) = default;
+
 Snippet::~Snippet() {
 }