components: default the user-defined empty ctor and dtor where possible

I need an owner's approval please for changes under:
components/browsing_data

This is a mechanical change. There are a few instances (but not all)
of empty user-defined constructors and destructors which can be
defaulted in the /components code.

A few of these have been missed by previous CLs and are being changed
now.

This CL was uploaded by git cl split.

R=ayui@chromium.org

Bug: 374110115
Change-Id: I3c3b3463297c4d816abbe1f14d6396d118bed649
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5961252
Reviewed-by: Martin Šrámek <msramek@chromium.org>
Auto-Submit: Sorin Jianu <sorin@chromium.org>
Commit-Queue: Martin Šrámek <msramek@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1374755}

components/browsing_data/core/counters/autofill_counter.cc

@@ -187,6 +187,6 @@ AutofillCounter::AutofillResult::AutofillResult(
       num_addresses_(num_addresses),
       num_user_annotation_entries_(num_user_annotation_entries) {}
 
-AutofillCounter::AutofillResult::~AutofillResult() {}
+AutofillCounter::AutofillResult::~AutofillResult() = default;
 
 }  // namespace browsing_data

components/browsing_data/core/counters/browsing_data_counter.cc

@@ -198,7 +198,7 @@ BrowsingDataCounter::Result::Result(const BrowsingDataCounter* source)
   DCHECK(source);
 }
 
-BrowsingDataCounter::Result::~Result() {}
+BrowsingDataCounter::Result::~Result() = default;
 
 bool BrowsingDataCounter::Result::Finished() const {
   return false;
@@ -211,7 +211,7 @@ BrowsingDataCounter::FinishedResult::FinishedResult(
     ResultInt value)
     : Result(source), value_(value) {}
 
-BrowsingDataCounter::FinishedResult::~FinishedResult() {}
+BrowsingDataCounter::FinishedResult::~FinishedResult() = default;
 
 bool BrowsingDataCounter::FinishedResult::Finished() const {
   return true;
@@ -229,6 +229,6 @@ BrowsingDataCounter::SyncResult::SyncResult(const BrowsingDataCounter* source,
                                             bool sync_enabled)
     : FinishedResult(source, value), sync_enabled_(sync_enabled) {}
 
-BrowsingDataCounter::SyncResult::~SyncResult() {}
+BrowsingDataCounter::SyncResult::~SyncResult() = default;
 
 }  // namespace browsing_data

components/browsing_data/core/counters/history_counter.cc

@@ -195,6 +195,6 @@ HistoryCounter::HistoryResult::HistoryResult(const HistoryCounter* source,
     : SyncResult(source, value, is_sync_enabled),
       has_synced_visits_(has_synced_visits) {}
 
-HistoryCounter::HistoryResult::~HistoryResult() {}
+HistoryCounter::HistoryResult::~HistoryResult() = default;
 
 }  // namespace browsing_data