Use `default` instead of empty body ctor and dtor definitions.

This is a mechanical change over files in the update_client,
component_updater, and the extension updater.

Change-Id: I2a5b682299cbb04bdfa9f5691329dfa97e869d2c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2104396
Reviewed-by: Joshua Pawlicki <[email protected]>
Commit-Queue: Sorin Jianu <[email protected]>
Cr-Commit-Position: refs/heads/master@{#750544}
diff --git a/components/update_client/update_client_unittest.cc b/components/update_client/update_client_unittest.cc
index 823ef42e..aa487eb 100644
--- a/components/update_client/update_client_unittest.cc
+++ b/components/update_client/update_client_unittest.cc
@@ -154,7 +154,7 @@
 MockPingManagerImpl::MockPingManagerImpl(scoped_refptr<Configurator> config)
     : PingManager(config) {}
 
-MockPingManagerImpl::~MockPingManagerImpl() {}
+MockPingManagerImpl::~MockPingManagerImpl() = default;
 
 void MockPingManagerImpl::SendPing(const Component& component,
                                    Callback callback) {
@@ -222,8 +222,7 @@
   PersistedData::RegisterPrefs(pref_->registry());
 }
 
-UpdateClientTest::~UpdateClientTest() {
-}
+UpdateClientTest::~UpdateClientTest() = default;
 
 void UpdateClientTest::RunThreads() {
   runloop_.Run();
@@ -3162,7 +3161,7 @@
 
    private:
     MockCrxDownloader() : CrxDownloader(nullptr) {}
-    ~MockCrxDownloader() override {}
+    ~MockCrxDownloader() override = default;
 
     void DoStartDownload(const GURL& url) override {}
   };