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/drive/sync_client.cc b/components/drive/sync_client.cc
index 3b71af3..e76d826e1 100644
--- a/components/drive/sync_client.cc
+++ b/components/drive/sync_client.cc
@@ -135,6 +135,7 @@
 
 SyncClient::SyncTask::SyncTask()
     : state(SUSPENDED), context(BACKGROUND), should_run_again(false) {}
+SyncClient::SyncTask::SyncTask(const SyncTask& other) = default;
 SyncClient::SyncTask::~SyncTask() {}
 
 SyncClient::SyncClient(base::SequencedTaskRunner* blocking_task_runner,