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

I need an owner's approval please for changes under:
['components/favicon', 'components/favicon_base', 'components/query_parser', 'components/sessions', 'components/visitedlink']

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.

This CL was uploaded by git cl split.

R=sky@chromium.org

Bug: 371316188
Change-Id: If2b363c364d8437b6a65434bacc49a73a033152f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5918669
Auto-Submit: Sorin Jianu <sorin@chromium.org>
Commit-Queue: Sorin Jianu <sorin@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1366386}

components/favicon/core/favicon_client.h

@@ -18,12 +18,12 @@ namespace favicon {
 // e.g. Chrome.
 class FaviconClient {
  public:
-  FaviconClient() {}
+  FaviconClient() = default;
 
   FaviconClient(const FaviconClient&) = delete;
   FaviconClient& operator=(const FaviconClient&) = delete;
 
-  virtual ~FaviconClient() {}
+  virtual ~FaviconClient() = default;
 
   // Returns true if the specified URL is a native application page URL.
   // If this returns true the favicon for the page must be fetched using

components/favicon/core/favicon_driver_observer.h

@@ -34,12 +34,12 @@ class FaviconDriverObserver {
     TOUCH_LARGEST
   };
 
-  FaviconDriverObserver() {}
+  FaviconDriverObserver() = default;
 
   FaviconDriverObserver(const FaviconDriverObserver&) = delete;
   FaviconDriverObserver& operator=(const FaviconDriverObserver&) = delete;
 
-  virtual ~FaviconDriverObserver() {}
+  virtual ~FaviconDriverObserver() = default;
 
   // Called when either:
   // 1) Chrome determines the best icon for the page for

components/favicon/core/favicon_service_impl.cc

@@ -51,7 +51,7 @@ FaviconServiceImpl::FaviconServiceImpl(
   CHECK(history_service_);
 }
 
-FaviconServiceImpl::~FaviconServiceImpl() {}
+FaviconServiceImpl::~FaviconServiceImpl() = default;
 
 base::CancelableTaskTracker::TaskId FaviconServiceImpl::GetFaviconImage(
     const GURL& icon_url,

components/favicon/core/history_ui_favicon_request_handler_impl.cc

@@ -70,7 +70,8 @@ HistoryUiFaviconRequestHandlerImpl::HistoryUiFaviconRequestHandlerImpl(
   DCHECK(large_icon_service);
 }
 
-HistoryUiFaviconRequestHandlerImpl::~HistoryUiFaviconRequestHandlerImpl() {}
+HistoryUiFaviconRequestHandlerImpl::~HistoryUiFaviconRequestHandlerImpl() =
+    default;
 
 void HistoryUiFaviconRequestHandlerImpl::GetRawFaviconForPageURL(
     const GURL& page_url,

components/favicon/core/large_icon_service.h

@@ -178,7 +178,7 @@ class LargeIconService : public KeyedService {
   // postpones the automatic eviction of the favicon from the database.
   virtual void TouchIconFromGoogleServer(const GURL& icon_url) = 0;
  protected:
-  LargeIconService() {}
+  LargeIconService() = default;
 };
 
 }  // namespace favicon

components/favicon/core/large_icon_service_impl.cc

@@ -192,7 +192,7 @@ LargeIconServiceImpl::LargeIconServiceImpl(
   // a DCHECK(image_fetcher_) here.
 }
 
-LargeIconServiceImpl::~LargeIconServiceImpl() {}
+LargeIconServiceImpl::~LargeIconServiceImpl() = default;
 
 base::CancelableTaskTracker::TaskId
 LargeIconServiceImpl::GetLargeIconRawBitmapOrFallbackStyleForPageUrl(

components/favicon/core/large_icon_service_impl_unittest.cc

@@ -109,7 +109,7 @@ class LargeIconServiceTest : public testing::Test {
   LargeIconServiceTest(const LargeIconServiceTest&) = delete;
   LargeIconServiceTest& operator=(const LargeIconServiceTest&) = delete;
 
-  ~LargeIconServiceTest() override {}
+  ~LargeIconServiceTest() override = default;
 
  protected:
   base::test::TaskEnvironment task_environment_;
@@ -438,7 +438,7 @@ class LargeIconServiceGetterTest : public LargeIconServiceTest,
   LargeIconServiceGetterTest& operator=(const LargeIconServiceGetterTest&) =
       delete;
 
-  ~LargeIconServiceGetterTest() override {}
+  ~LargeIconServiceGetterTest() override = default;
 
   void ExpectFetchImageFromGoogleServer() {
     EXPECT_CALL(*mock_image_fetcher_,

components/favicon_base/favicon_types.cc

@@ -11,9 +11,9 @@ namespace favicon_base {
 // ---------------------------------------------------------
 // FaviconImageResult
 
-FaviconImageResult::FaviconImageResult() {}
+FaviconImageResult::FaviconImageResult() = default;
 
-FaviconImageResult::~FaviconImageResult() {}
+FaviconImageResult::~FaviconImageResult() = default;
 
 // --------------------------------------------------------
 // FaviconRawBitmapResult
@@ -24,7 +24,7 @@ FaviconRawBitmapResult::FaviconRawBitmapResult()
 FaviconRawBitmapResult::FaviconRawBitmapResult(
     const FaviconRawBitmapResult& other) = default;
 
-FaviconRawBitmapResult::~FaviconRawBitmapResult() {}
+FaviconRawBitmapResult::~FaviconRawBitmapResult() = default;
 
 // --------------------------------------------------------
 // LargeIconResult
@@ -35,7 +35,7 @@ LargeIconResult::LargeIconResult(const FaviconRawBitmapResult& bitmap_in)
 LargeIconResult::LargeIconResult(FallbackIconStyle* fallback_icon_style_in)
     : fallback_icon_style(fallback_icon_style_in) {}
 
-LargeIconResult::~LargeIconResult() {}
+LargeIconResult::~LargeIconResult() = default;
 
 LargeIconResult::LargeIconResult(LargeIconResult&& result) = default;
 
@@ -50,6 +50,6 @@ LargeIconImageResult::LargeIconImageResult(
     FallbackIconStyle* fallback_icon_style_in)
     : fallback_icon_style(fallback_icon_style_in) {}
 
-LargeIconImageResult::~LargeIconImageResult() {}
+LargeIconImageResult::~LargeIconImageResult() = default;
 
 }  // namespace favicon_base

components/favicon_base/select_favicon_frames.cc

@@ -173,12 +173,12 @@ SkBitmap GetResizedBitmap(const SkBitmap& source_bitmap,
 
 class FaviconImageSource : public gfx::ImageSkiaSource {
  public:
-  FaviconImageSource() {}
+  FaviconImageSource() = default;
 
   FaviconImageSource(const FaviconImageSource&) = delete;
   FaviconImageSource& operator=(const FaviconImageSource&) = delete;
 
-  ~FaviconImageSource() override {}
+  ~FaviconImageSource() override = default;
 
   // gfx::ImageSkiaSource:
   gfx::ImageSkiaRep GetImageForScale(float scale) override {

components/query_parser/query_parser.cc

@@ -100,7 +100,7 @@ QueryNodeWord::QueryNodeWord(const std::u16string& word,
                              MatchingAlgorithm matching_algorithm)
     : word_(word), literal_(false), matching_algorithm_(matching_algorithm) {}
 
-QueryNodeWord::~QueryNodeWord() {}
+QueryNodeWord::~QueryNodeWord() = default;
 
 int QueryNodeWord::AppendToSQLiteQuery(std::u16string* query) const {
   query->append(word_);
@@ -180,7 +180,7 @@ class QueryNodeList : public QueryNode {
   QueryNodeVector children_;
 };
 
-QueryNodeList::QueryNodeList() {}
+QueryNodeList::QueryNodeList() = default;
 
 QueryNodeList::~QueryNodeList() {
 }
@@ -266,9 +266,9 @@ class QueryNodePhrase : public QueryNodeList {
                   const QueryWord** last_word) const;
 };
 
-QueryNodePhrase::QueryNodePhrase() {}
+QueryNodePhrase::QueryNodePhrase() = default;
 
-QueryNodePhrase::~QueryNodePhrase() {}
+QueryNodePhrase::~QueryNodePhrase() = default;
 
 int QueryNodePhrase::AppendToSQLiteQuery(std::u16string* query) const {
   query->push_back(L'"');

components/query_parser/query_parser.h

@@ -42,7 +42,7 @@ using QueryWordVector = std::vector<query_parser::QueryWord>;
 // really isn't meant for external usage.
 class QueryNode {
  public:
-  virtual ~QueryNode() {}
+  virtual ~QueryNode() = default;
 
   // Serialize ourselves out to a string that can be passed to SQLite. Returns
   // the number of words in this node.

components/sessions/content/content_live_tab.cc

@@ -31,7 +31,7 @@ ContentLiveTab* ContentLiveTab::GetForWebContents(
 ContentLiveTab::ContentLiveTab(content::WebContents* contents)
     : web_contents_(contents) {}
 
-ContentLiveTab::~ContentLiveTab() {}
+ContentLiveTab::~ContentLiveTab() = default;
 
 bool ContentLiveTab::IsInitialBlankNavigation() {
   return navigation_controller().IsInitialBlankNavigation();

components/sessions/content/content_serialized_navigation_builder_unittest.cc

@@ -48,7 +48,7 @@ class TestExtendedInfoHandler : public ExtendedInfoHandler {
   TestExtendedInfoHandler(const TestExtendedInfoHandler&) = delete;
   TestExtendedInfoHandler& operator=(const TestExtendedInfoHandler&) = delete;
 
-  ~TestExtendedInfoHandler() override {}
+  ~TestExtendedInfoHandler() override = default;
 
   // ExtendedInfoHandler:
   std::string GetExtendedInfo(content::NavigationEntry* entry) const override {
@@ -111,14 +111,14 @@ void SetExtendedInfoForTest(content::NavigationEntry* entry) {
 
 class ContentSerializedNavigationBuilderTest : public testing::Test {
  public:
-  ContentSerializedNavigationBuilderTest() {}
+  ContentSerializedNavigationBuilderTest() = default;
 
   ContentSerializedNavigationBuilderTest(
       const ContentSerializedNavigationBuilderTest&) = delete;
   ContentSerializedNavigationBuilderTest& operator=(
       const ContentSerializedNavigationBuilderTest&) = delete;
 
-  ~ContentSerializedNavigationBuilderTest() override {}
+  ~ContentSerializedNavigationBuilderTest() override = default;
 
   void SetUp() override {
     ContentSerializedNavigationDriver* driver =

components/sessions/content/extended_info_handler.h

@@ -22,8 +22,8 @@ namespace sessions {
 // Chrome.
 class SESSIONS_EXPORT ExtendedInfoHandler {
  public:
-  ExtendedInfoHandler() {}
-  virtual ~ExtendedInfoHandler() {}
+  ExtendedInfoHandler() = default;
+  virtual ~ExtendedInfoHandler() = default;
 
   // Returns the data to write to disk for the specified NavigationEntry.
   virtual std::string GetExtendedInfo(

components/sessions/content/navigation_task_id.cc

@@ -11,12 +11,12 @@
 namespace sessions {
 const char kTaskIdKey[] = "task_id_data";
 
-NavigationTaskId::NavigationTaskId() {}
+NavigationTaskId::NavigationTaskId() = default;
 
 NavigationTaskId::NavigationTaskId(const NavigationTaskId& navigation_task_id) =
     default;
 
-NavigationTaskId::~NavigationTaskId() {}
+NavigationTaskId::~NavigationTaskId() = default;
 
 NavigationTaskId* NavigationTaskId::Get(content::NavigationEntry* entry) {
   NavigationTaskId* navigation_task_id =

components/sessions/content/navigation_task_id_unittest.cc

@@ -12,12 +12,12 @@ namespace sessions {
 
 class NavigationTaskIDTest : public testing::Test {
  public:
-  NavigationTaskIDTest() {}
+  NavigationTaskIDTest() = default;
 
   NavigationTaskIDTest(const NavigationTaskIDTest&) = delete;
   NavigationTaskIDTest& operator=(const NavigationTaskIDTest&) = delete;
 
-  ~NavigationTaskIDTest() override {}
+  ~NavigationTaskIDTest() override = default;
 
   void SetUp() override {
     navigation_entry_ = content::NavigationEntry::Create();

components/sessions/core/command_storage_manager_delegate.h

@@ -15,7 +15,7 @@ namespace sessions {
 // chrome/content dependencies.
 class CommandStorageManagerDelegate {
  public:
-  CommandStorageManagerDelegate() {}
+  CommandStorageManagerDelegate() = default;
 
   // Returns true if save operations can be performed as a delayed task - which
   // is usually only used by unit tests.
@@ -34,7 +34,7 @@ class CommandStorageManagerDelegate {
   virtual void OnErrorWritingSessionCommands() = 0;
 
  protected:
-  virtual ~CommandStorageManagerDelegate() {}
+  virtual ~CommandStorageManagerDelegate() = default;
 };
 
 }  // namespace sessions

components/sessions/core/live_tab.cc

@@ -6,7 +6,7 @@
 
 namespace sessions {
 
-LiveTab::~LiveTab() {}
+LiveTab::~LiveTab() = default;
 
 std::unique_ptr<tab_restore::PlatformSpecificTabData>
 LiveTab::GetPlatformSpecificTabData() {

components/sessions/core/live_tab_context.h

@@ -87,7 +87,7 @@ class SESSIONS_EXPORT LiveTabContext {
   virtual void CloseTab() = 0;
 
  protected:
-  virtual ~LiveTabContext() {}
+  virtual ~LiveTabContext() = default;
 };
 
 }  // namespace sessions

components/sessions/core/serialized_navigation_driver.h

@@ -38,7 +38,7 @@ class SESSIONS_EXPORT SerializedNavigationDriver {
       const std::string& page_state) const = 0;
 
  protected:
-  virtual ~SerializedNavigationDriver() {}
+  virtual ~SerializedNavigationDriver() = default;
 };
 
 }  // namespace sessions

components/sessions/core/session_id_generator.cc

@@ -96,7 +96,7 @@ SessionIdGenerator::SessionIdGenerator()
       last_value_(0),
       rand_generator_(base::BindRepeating(&DefaultRandGenerator)) {}
 
-SessionIdGenerator::~SessionIdGenerator() {}
+SessionIdGenerator::~SessionIdGenerator() = default;
 
 void SessionIdGenerator::IncrementValueBy(int increment) {
   DCHECK_LT(0, increment);

components/sessions/core/session_types.cc

@@ -28,7 +28,7 @@ SessionTab::~SessionTab() {
 
 SessionTabGroup::SessionTabGroup(const tab_groups::TabGroupId& id) : id(id) {}
 
-SessionTabGroup::~SessionTabGroup() {}
+SessionTabGroup::~SessionTabGroup() = default;
 
 // SessionWindow ---------------------------------------------------------------
 
@@ -40,6 +40,6 @@ SessionWindow::SessionWindow()
       is_constrained(true),
       show_state(ui::mojom::WindowShowState::kDefault) {}
 
-SessionWindow::~SessionWindow() {}
+SessionWindow::~SessionWindow() = default;
 
 }  // namespace sessions

components/sessions/core/tab_restore_service_client.cc

@@ -6,7 +6,7 @@
 
 namespace sessions {
 
-TabRestoreServiceClient::~TabRestoreServiceClient() {}
+TabRestoreServiceClient::~TabRestoreServiceClient() = default;
 
 void TabRestoreServiceClient::OnTabRestored(const GURL& url) {}
 

components/sessions/core/tab_restore_service_observer.h

@@ -26,7 +26,7 @@ class SESSIONS_EXPORT TabRestoreServiceObserver {
   virtual void TabRestoreServiceLoaded(TabRestoreService* service) {}
 
  protected:
-  virtual ~TabRestoreServiceObserver() {}
+  virtual ~TabRestoreServiceObserver() = default;
 };
 
 }  // namespace sessions

components/sessions/ios/ios_live_tab.mm

@@ -7,6 +7,6 @@
 
 namespace sessions {
 
-IOSLiveTab::~IOSLiveTab() {}
+IOSLiveTab::~IOSLiveTab() = default;
 
 }  // namespace sessions

components/sessions/ios/ios_restore_live_tab.mm

@@ -11,7 +11,7 @@ namespace sessions {
 RestoreIOSLiveTab::RestoreIOSLiveTab(web::proto::NavigationStorage storage)
     : storage_(std::move(storage)) {}
 
-RestoreIOSLiveTab::~RestoreIOSLiveTab() {}
+RestoreIOSLiveTab::~RestoreIOSLiveTab() = default;
 
 bool RestoreIOSLiveTab::IsInitialBlankNavigation() {
   return false;

components/sessions/ios/ios_webstate_live_tab.mm

@@ -28,7 +28,7 @@ IOSWebStateLiveTab* IOSWebStateLiveTab::GetForWebState(
 IOSWebStateLiveTab::IOSWebStateLiveTab(web::WebState* web_state)
     : web_state_(web_state) {}
 
-IOSWebStateLiveTab::~IOSWebStateLiveTab() {}
+IOSWebStateLiveTab::~IOSWebStateLiveTab() = default;
 
 bool IOSWebStateLiveTab::IsInitialBlankNavigation() {
   return navigation_manager()->GetItemCount() == 0;

components/visitedlink/browser/partitioned_visitedlink_writer.h

@@ -42,7 +42,7 @@ class PartitionedVisitedLinkWriter : public VisitedLinkCommon {
   // event as a constructor argument and dispatches events using it.
   class Listener {
    public:
-    virtual ~Listener() {}
+    virtual ~Listener() = default;
 
     // Called when link coloring database has been created or replaced. The
     // argument is a memory region containing the new table.
@@ -102,7 +102,7 @@ class PartitionedVisitedLinkWriter : public VisitedLinkCommon {
     virtual bool HasNextVisitedLink() const = 0;
 
    protected:
-    virtual ~VisitedLinkIterator() {}
+    virtual ~VisitedLinkIterator() = default;
   };
 
   // Deletes the specified VisitedLinks from the hashtable.

components/visitedlink/browser/visitedlink_delegate.h

@@ -34,7 +34,7 @@ class VisitedLinkDelegate {
     virtual void OnComplete(bool success) = 0;
 
    protected:
-    virtual ~URLEnumerator() {}
+    virtual ~URLEnumerator() = default;
 
    private:
     friend class base::RefCountedThreadSafe<URLEnumerator>;
@@ -76,7 +76,7 @@ class VisitedLinkDelegate {
       const scoped_refptr<VisitedLinkEnumerator>& enumerator) = 0;
 
  protected:
-  virtual ~VisitedLinkDelegate() {}
+  virtual ~VisitedLinkDelegate() = default;
 };
 
 }  // namespace visitedlink

components/visitedlink/browser/visitedlink_writer.cc

@@ -219,7 +219,7 @@ class VisitedLinkWriter::TableBuilder
   void OnComplete(bool succeed) override;
 
  private:
-  ~TableBuilder() override {}
+  ~TableBuilder() override = default;
 
   // OnComplete mashals to this function on the main thread to do the
   // notification.

components/visitedlink/browser/visitedlink_writer.h

@@ -63,7 +63,7 @@ class VisitedLinkWriter : public VisitedLinkCommon {
   // event as a constructor argument and dispatches events using it.
   class Listener {
    public:
-    virtual ~Listener() {}
+    virtual ~Listener() = default;
 
     // Called when link coloring database has been created or replaced. The
     // argument is a memory region containing the new table.
@@ -140,7 +140,7 @@ class VisitedLinkWriter : public VisitedLinkCommon {
     virtual bool HasNextURL() const = 0;
 
    protected:
-    virtual ~URLIterator() {}
+    virtual ~URLIterator() = default;
   };
 
   // Deletes the specified URLs from |rows| from the table.

components/visitedlink/test/visitedlink_perftest.cc

@@ -100,7 +100,7 @@ GURL TestURL(const char* prefix, int i) {
 // We have no readers, so all methods on this listener are a no-ops.
 class DummyVisitedLinkEventListener : public VisitedLinkWriter::Listener {
  public:
-  DummyVisitedLinkEventListener() {}
+  DummyVisitedLinkEventListener() = default;
   void NewTable(base::ReadOnlySharedMemoryRegion*) override {}
   void Add(VisitedLinkCommon::Fingerprint) override {}
   void Reset(bool invalidate_hashes) override {}