[cleanup] Refactor second batch of general classes to use default members.

Fixing clang-tidy warning.

Bug: v8:8015
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: Ibc5124e06f5774e7695029e2d21084a7efb965e6
Reviewed-on: https://chromium-review.googlesource.com/1224412
Commit-Queue: Florian Sattler <sattlerf@google.com>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56065}

include/libplatform/v8-tracing.h

@@ -35,7 +35,7 @@ class V8_PLATFORM_EXPORT TraceObject {
     const char* as_string;
   };
 
-  TraceObject() {}
+  TraceObject() = default;
   ~TraceObject();
   void Initialize(
       char phase, const uint8_t* category_enabled_flag, const char* name,
@@ -106,8 +106,8 @@ class V8_PLATFORM_EXPORT TraceObject {
 
 class V8_PLATFORM_EXPORT TraceWriter {
  public:
-  TraceWriter() {}
-  virtual ~TraceWriter() {}
+  TraceWriter() = default;
+  virtual ~TraceWriter() = default;
   virtual void AppendTraceEvent(TraceObject* trace_event) = 0;
   virtual void Flush() = 0;
 
@@ -147,8 +147,8 @@ class V8_PLATFORM_EXPORT TraceBufferChunk {
 
 class V8_PLATFORM_EXPORT TraceBuffer {
  public:
-  TraceBuffer() {}
-  virtual ~TraceBuffer() {}
+  TraceBuffer() = default;
+  virtual ~TraceBuffer() = default;
 
   virtual TraceObject* AddTraceEvent(uint64_t* handle) = 0;
   virtual TraceObject* GetEventByHandle(uint64_t handle) = 0;

include/v8-profiler.h

@@ -445,7 +445,7 @@ class V8_EXPORT OutputStream {  // NOLINT
     kContinue = 0,
     kAbort = 1
   };
-  virtual ~OutputStream() {}
+  virtual ~OutputStream() = default;
   /** Notify about the end of stream. */
   virtual void EndOfStream() = 0;
   /** Get preferred output chunk size. Called only once. */
@@ -539,7 +539,7 @@ class V8_EXPORT ActivityControl {  // NOLINT
     kContinue = 0,
     kAbort = 1
   };
-  virtual ~ActivityControl() {}
+  virtual ~ActivityControl() = default;
   /**
    * Notify about current progress. The activity can be stopped by
    * returning kAbort as the callback result.
@@ -625,7 +625,7 @@ class V8_EXPORT AllocationProfile {
    */
   virtual Node* GetRootNode() = 0;
 
-  virtual ~AllocationProfile() {}
+  virtual ~AllocationProfile() = default;
 
   static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
   static const int kNoColumnNumberInfo = Message::kNoColumnInfo;
@@ -793,7 +793,7 @@ class V8_EXPORT HeapProfiler {
     virtual const char* GetName(Local<Object> object) = 0;
 
    protected:
-    virtual ~ObjectNameResolver() {}
+    virtual ~ObjectNameResolver() = default;
   };
 
   /**
@@ -985,8 +985,8 @@ class V8_EXPORT RetainedObjectInfo {  // NOLINT
   virtual intptr_t GetSizeInBytes() { return -1; }
 
  protected:
-  RetainedObjectInfo() {}
-  virtual ~RetainedObjectInfo() {}
+  RetainedObjectInfo() = default;
+  virtual ~RetainedObjectInfo() = default;
 
  private:
   RetainedObjectInfo(const RetainedObjectInfo&);

include/v8.h

@@ -855,7 +855,7 @@ class V8_EXPORT HandleScope {
   void operator=(const HandleScope&) = delete;
 
  protected:
-  V8_INLINE HandleScope() {}
+  V8_INLINE HandleScope() = default;
 
   void Initialize(Isolate* isolate);
 
@@ -895,7 +895,7 @@ class V8_EXPORT HandleScope {
 class V8_EXPORT EscapableHandleScope : public HandleScope {
  public:
   explicit EscapableHandleScope(Isolate* isolate);
-  V8_INLINE ~EscapableHandleScope() {}
+  V8_INLINE ~EscapableHandleScope() = default;
 
   /**
    * Pushes the value into the previous scope and returns a handle to it.
@@ -1337,7 +1337,7 @@ class V8_EXPORT ScriptCompiler {
    */
   class V8_EXPORT ExternalSourceStream {
    public:
-    virtual ~ExternalSourceStream() {}
+    virtual ~ExternalSourceStream() = default;
 
     /**
      * V8 calls this to request the next chunk of data from the embedder. This
@@ -1415,7 +1415,7 @@ class V8_EXPORT ScriptCompiler {
    */
   class ScriptStreamingTask {
    public:
-    virtual ~ScriptStreamingTask() {}
+    virtual ~ScriptStreamingTask() = default;
     virtual void Run() = 0;
   };
 
@@ -1868,7 +1868,7 @@ class V8_EXPORT ValueSerializer {
  public:
   class V8_EXPORT Delegate {
    public:
-    virtual ~Delegate() {}
+    virtual ~Delegate() = default;
 
     /**
      * Handles the case where a DataCloneError would be thrown in the structured
@@ -2005,7 +2005,7 @@ class V8_EXPORT ValueDeserializer {
  public:
   class V8_EXPORT Delegate {
    public:
-    virtual ~Delegate() {}
+    virtual ~Delegate() = default;
 
     /**
      * The embedder overrides this method to read some kind of host object, if
@@ -2620,7 +2620,7 @@ class V8_EXPORT String : public Name {
 
   class V8_EXPORT ExternalStringResourceBase {  // NOLINT
    public:
-    virtual ~ExternalStringResourceBase() {}
+    virtual ~ExternalStringResourceBase() = default;
 
     V8_DEPRECATE_SOON("Use IsCacheable().",
                       virtual bool IsCompressible() const) {
@@ -2644,7 +2644,7 @@ class V8_EXPORT String : public Name {
     }
 
    protected:
-    ExternalStringResourceBase() {}
+    ExternalStringResourceBase() = default;
 
     /**
      * Internally V8 will call this Dispose method when the external string
@@ -2695,7 +2695,7 @@ class V8_EXPORT String : public Name {
      * Override the destructor to manage the life cycle of the underlying
      * buffer.
      */
-    ~ExternalStringResource() override {}
+    ~ExternalStringResource() override = default;
 
     /**
      * The string data from the underlying buffer.
@@ -2708,7 +2708,7 @@ class V8_EXPORT String : public Name {
     virtual size_t length() const = 0;
 
    protected:
-    ExternalStringResource() {}
+    ExternalStringResource() = default;
   };
 
   /**
@@ -2728,13 +2728,13 @@ class V8_EXPORT String : public Name {
      * Override the destructor to manage the life cycle of the underlying
      * buffer.
      */
-    ~ExternalOneByteStringResource() override {}
+    ~ExternalOneByteStringResource() override = default;
     /** The string data from the underlying buffer.*/
     virtual const char* data() const = 0;
     /** The number of Latin-1 characters in the string.*/
     virtual size_t length() const = 0;
    protected:
-    ExternalOneByteStringResource() {}
+    ExternalOneByteStringResource() = default;
   };
 
   /**
@@ -4404,7 +4404,7 @@ class V8_EXPORT WasmModuleObjectBuilderStreaming final {
   void Abort(MaybeLocal<Value> exception);
   Local<Promise> GetPromise();
 
-  ~WasmModuleObjectBuilderStreaming();
+  ~WasmModuleObjectBuilderStreaming() = default;
 
  private:
   WasmModuleObjectBuilderStreaming(const WasmModuleObjectBuilderStreaming&) =
@@ -4463,7 +4463,7 @@ class V8_EXPORT ArrayBuffer : public Object {
    */
   class V8_EXPORT Allocator { // NOLINT
    public:
-    virtual ~Allocator() {}
+    virtual ~Allocator() = default;
 
     /**
      * Allocate |length| bytes. Return NULL if allocation is not successful.
@@ -6891,7 +6891,7 @@ typedef void (*JitCodeEventHandler)(const JitCodeEvent* event);
  */
 class V8_EXPORT ExternalResourceVisitor {  // NOLINT
  public:
-  virtual ~ExternalResourceVisitor() {}
+  virtual ~ExternalResourceVisitor() = default;
   virtual void VisitExternalString(Local<String> string) {}
 };
 
@@ -6901,7 +6901,7 @@ class V8_EXPORT ExternalResourceVisitor {  // NOLINT
  */
 class V8_EXPORT PersistentHandleVisitor {  // NOLINT
  public:
-  virtual ~PersistentHandleVisitor() {}
+  virtual ~PersistentHandleVisitor() = default;
   virtual void VisitPersistentHandle(Persistent<Value>* value,
                                      uint16_t class_id) {}
 };

src/api.cc

@@ -7452,9 +7452,6 @@ void WasmModuleObjectBuilderStreaming::Finish() {
 void WasmModuleObjectBuilderStreaming::Abort(MaybeLocal<Value> exception) {
 }
 
-WasmModuleObjectBuilderStreaming::~WasmModuleObjectBuilderStreaming() {
-}
-
 // static
 v8::ArrayBuffer::Allocator* v8::ArrayBuffer::Allocator::NewDefaultAllocator() {
   return new ArrayBufferAllocator();
@@ -9744,7 +9741,7 @@ debug::PostponeInterruptsScope::PostponeInterruptsScope(v8::Isolate* isolate)
           new i::PostponeInterruptsScope(reinterpret_cast<i::Isolate*>(isolate),
                                          i::StackGuard::API_INTERRUPT)) {}
 
-debug::PostponeInterruptsScope::~PostponeInterruptsScope() {}
+debug::PostponeInterruptsScope::~PostponeInterruptsScope() = default;
 
 Local<String> CpuProfileNode::GetFunctionName() const {
   const i::ProfileNode* node = reinterpret_cast<const i::ProfileNode*>(this);

src/assembler.h

@@ -364,12 +364,12 @@ class CpuFeatureScope {
 #else
   CpuFeatureScope(AssemblerBase* assembler, CpuFeature f,
                   CheckPolicy check = kCheckSupported) {}
-  // Define a destructor to avoid unused variable warnings.
-  ~CpuFeatureScope() {}
+  ~CpuFeatureScope() {
+    // Define a destructor to avoid unused variable warnings.
+  }
 #endif
 };
 
-
 // CpuFeatures keeps track of which features are supported by the target CPU.
 // Supported features must be enabled by a CpuFeatureScope before use.
 // Example:
@@ -444,7 +444,7 @@ double power_double_double(double x, double y);
 
 class ConstantPoolEntry {
  public:
-  ConstantPoolEntry() {}
+  ConstantPoolEntry() = default;
   ConstantPoolEntry(int position, intptr_t value, bool sharing_ok,
                     RelocInfo::Mode rmode = RelocInfo::NONE)
       : position_(position),

src/assert-scope.h

@@ -77,7 +77,9 @@ class PerThreadAssertScopeDebugOnly : public
 #else
 class PerThreadAssertScopeDebugOnly {
  public:
-  PerThreadAssertScopeDebugOnly() { }
+  PerThreadAssertScopeDebugOnly() {
+    // Define a constructor to avoid unused variable warnings.
+  }
   void Release() {}
 #endif
 };

src/basic-block-profiler.cc

@@ -27,9 +27,6 @@ BasicBlockProfiler::Data::Data(size_t n_blocks)
       block_rpo_numbers_(n_blocks_),
       counts_(n_blocks_, 0) {}
 
-BasicBlockProfiler::Data::~Data() {}
-
-
 static void InsertIntoString(std::ostringstream* os, std::string* string) {
   string->insert(0, os->str());
 }
@@ -68,10 +65,6 @@ void BasicBlockProfiler::Data::ResetCounts() {
   }
 }
 
-
-BasicBlockProfiler::BasicBlockProfiler() {}
-
-
 BasicBlockProfiler::Data* BasicBlockProfiler::NewData(size_t n_blocks) {
   base::LockGuard<base::Mutex> lock(&data_list_mutex_);
   Data* data = new Data(n_blocks);

src/basic-block-profiler.h

@@ -36,7 +36,7 @@ class BasicBlockProfiler {
                                     const BasicBlockProfiler::Data& s);
 
     explicit Data(size_t n_blocks);
-    ~Data();
+    ~Data() = default;
 
     void ResetCounts();
 
@@ -51,7 +51,7 @@ class BasicBlockProfiler {
 
   typedef std::list<Data*> DataList;
 
-  BasicBlockProfiler();
+  BasicBlockProfiler() = default;
   ~BasicBlockProfiler();
 
   V8_EXPORT_PRIVATE static BasicBlockProfiler* Get();

src/bit-vector.h

@@ -31,7 +31,7 @@ class BitVector : public ZoneObject {
           current_(-1) {
       Advance();
     }
-    ~Iterator() {}
+    ~Iterator() = default;
 
     bool Done() const { return current_index_ >= target_->data_length_; }
     void Advance();

src/bootstrapper.cc

@@ -160,7 +160,7 @@ class Genesis {
           GlobalContextType context_type);
   Genesis(Isolate* isolate, MaybeHandle<JSGlobalProxy> maybe_global_proxy,
           v8::Local<v8::ObjectTemplate> global_proxy_template);
-  ~Genesis() { }
+  ~Genesis() = default;
 
   Isolate* isolate() const { return isolate_; }
   Factory* factory() const { return isolate_->factory(); }

src/builtins/builtins-collections-gen.cc

@@ -24,7 +24,7 @@ class BaseCollectionsAssembler : public CodeStubAssembler {
   explicit BaseCollectionsAssembler(compiler::CodeAssemblerState* state)
       : CodeStubAssembler(state) {}
 
-  virtual ~BaseCollectionsAssembler() {}
+  virtual ~BaseCollectionsAssembler() = default;
 
  protected:
   enum Variant { kMap, kSet, kWeakMap, kWeakSet };

src/collector.h

@@ -184,7 +184,7 @@ class SequenceCollector : public Collector<T, growth_factor, max_growth> {
       : Collector<T, growth_factor, max_growth>(initial_capacity),
         sequence_start_(kNoSequence) {}
 
-  ~SequenceCollector() override {}
+  ~SequenceCollector() override = default;
 
   void StartSequence() {
     DCHECK_EQ(sequence_start_, kNoSequence);

src/compilation-cache.cc

@@ -34,8 +34,6 @@ CompilationCache::CompilationCache(Isolate* isolate)
   }
 }
 
-CompilationCache::~CompilationCache() {}
-
 Handle<CompilationCacheTable> CompilationSubCache::GetTable(int generation) {
   DCHECK(generation < generations_);
   Handle<CompilationCacheTable> result;

src/compilation-cache.h

@@ -213,7 +213,7 @@ class CompilationCache {
 
  private:
   explicit CompilationCache(Isolate* isolate);
-  ~CompilationCache();
+  ~CompilationCache() = default;
 
   base::HashMap* EagerOptimizingSet();
 

src/compilation-statistics.h

@@ -24,7 +24,7 @@ struct AsPrintableStatistics {
 
 class CompilationStatistics final : public Malloced {
  public:
-  CompilationStatistics() {}
+  CompilationStatistics() = default;
 
   class BasicStats {
    public:

src/conversions.cc

@@ -194,7 +194,7 @@ class StringToIntHelper {
   // buffer of one-byte digits, along with an optional radix prefix.
   StringToIntHelper(Isolate* isolate, const uint8_t* subject, int length)
       : isolate_(isolate), raw_one_byte_subject_(subject), length_(length) {}
-  virtual ~StringToIntHelper() {}
+  virtual ~StringToIntHelper() = default;
 
  protected:
   // Subclasses must implement these:

src/counters.h

@@ -98,7 +98,7 @@ class StatsCounterBase {
   const char* name_;
   int* ptr_;
 
-  StatsCounterBase() {}
+  StatsCounterBase() = default;
   StatsCounterBase(Counters* counters, const char* name)
       : counters_(counters), name_(name), ptr_(nullptr) {}
 
@@ -161,7 +161,7 @@ class StatsCounter : public StatsCounterBase {
  private:
   friend class Counters;
 
-  StatsCounter() {}
+  StatsCounter() = default;
   StatsCounter(Counters* counters, const char* name)
       : StatsCounterBase(counters, name), lookup_done_(false) {}
 
@@ -227,7 +227,7 @@ class Histogram {
   }
 
  protected:
-  Histogram() {}
+  Histogram() = default;
   Histogram(const char* name, int min, int max, int num_buckets,
             Counters* counters)
       : name_(name),
@@ -277,7 +277,7 @@ class TimedHistogram : public Histogram {
   friend class Counters;
   HistogramTimerResolution resolution_;
 
-  TimedHistogram() {}
+  TimedHistogram() = default;
   TimedHistogram(const char* name, int min, int max,
                  HistogramTimerResolution resolution, int num_buckets,
                  Counters* counters)
@@ -393,7 +393,7 @@ class HistogramTimer : public TimedHistogram {
 
   base::ElapsedTimer timer_;
 
-  HistogramTimer() {}
+  HistogramTimer() = default;
 };
 
 // Helper class for scoping a HistogramTimer.
@@ -487,7 +487,7 @@ class AggregatableHistogramTimer : public Histogram {
  private:
   friend class Counters;
 
-  AggregatableHistogramTimer() {}
+  AggregatableHistogramTimer() = default;
   AggregatableHistogramTimer(const char* name, int min, int max,
                              int num_buckets, Counters* counters)
       : Histogram(name, min, max, num_buckets, counters) {}

src/deoptimizer.h

@@ -289,7 +289,7 @@ class TranslatedFrame {
 
 class TranslatedState {
  public:
-  TranslatedState() {}
+  TranslatedState() = default;
   explicit TranslatedState(const JavaScriptFrame* frame);
 
   void Prepare(Address stack_frame_pointer);
@@ -394,7 +394,7 @@ class TranslatedState {
 
 class OptimizedFunctionVisitor {
  public:
-  virtual ~OptimizedFunctionVisitor() {}
+  virtual ~OptimizedFunctionVisitor() = default;
   virtual void VisitFunction(JSFunction* function) = 0;
 };
 

src/disasm.h

@@ -16,7 +16,7 @@ typedef unsigned char byte;
 // specific.
 class NameConverter {
  public:
-  virtual ~NameConverter() {}
+  virtual ~NameConverter() = default;
   virtual const char* NameOfCPURegister(int reg) const;
   virtual const char* NameOfByteCPURegister(int reg) const;
   virtual const char* NameOfXMMRegister(int reg) const;

src/elements.cc

@@ -10,6 +10,7 @@
 #include "src/heap/factory.h"
 #include "src/heap/heap-write-barrier-inl.h"
 #include "src/isolate-inl.h"
+#include "src/keys.h"
 #include "src/messages.h"
 #include "src/objects-inl.h"
 #include "src/objects/arguments-inl.h"

src/elements.h

@@ -19,7 +19,7 @@ class JSTypedArray;
 class ElementsAccessor {
  public:
   explicit ElementsAccessor(const char* name) : name_(name) { }
-  virtual ~ElementsAccessor() { }
+  virtual ~ElementsAccessor() = default;
 
   const char* name() const { return name_; }
 

src/external-reference-table.h

@@ -73,7 +73,7 @@ class ExternalReferenceTable {
     return OffsetOfEntry(size()) + 2 * kUInt32Size;
   }
 
-  ExternalReferenceTable() {}
+  ExternalReferenceTable() = default;
   void Init(Isolate* isolate);
 
  private:

src/frames.h

@@ -300,7 +300,7 @@ class StackFrame {
 
  protected:
   inline explicit StackFrame(StackFrameIteratorBase* iterator);
-  virtual ~StackFrame() { }
+  virtual ~StackFrame() = default;
 
   // Compute the stack pointer for the calling frame.
   virtual Address GetCallerStackPointer() const = 0;

src/gdb-jit.cc

@@ -177,7 +177,7 @@ class ELFStringTable;
 template<typename THeader>
 class DebugSectionBase : public ZoneObject {
  public:
-  virtual ~DebugSectionBase() { }
+  virtual ~DebugSectionBase() = default;
 
   virtual void WriteBody(Writer::Slot<THeader> header, Writer* writer) {
     uintptr_t start = writer->position();
@@ -238,7 +238,7 @@ class MachOSection : public DebugSectionBase<MachOSectionHeader> {
     }
   }
 
-  ~MachOSection() override {}
+  ~MachOSection() override = default;
 
   virtual void PopulateHeader(Writer::Slot<Header> header) {
     header->addr = 0;
@@ -314,7 +314,7 @@ class ELFSection : public DebugSectionBase<ELFSectionHeader> {
   ELFSection(const char* name, Type type, uintptr_t align)
       : name_(name), type_(type), align_(align) { }
 
-  ~ELFSection() override {}
+  ~ELFSection() override = default;
 
   void PopulateHeader(Writer::Slot<Header> header, ELFStringTable* strtab);
 

src/handles.h

@@ -319,7 +319,7 @@ class SealHandleScope final {
  public:
 #ifndef DEBUG
   explicit SealHandleScope(Isolate* isolate) {}
-  ~SealHandleScope() {}
+  ~SealHandleScope() = default;
 #else
   explicit inline SealHandleScope(Isolate* isolate);
   inline ~SealHandleScope();

src/ic/ic.h

@@ -36,7 +36,7 @@ class IC {
   // Construct the IC structure with the given number of extra
   // JavaScript frames on the stack.
   IC(Isolate* isolate, Handle<FeedbackVector> vector, FeedbackSlot slot);
-  virtual ~IC() {}
+  virtual ~IC() = default;
 
   State state() const { return state_; }
   inline Address address() const;

src/interface-descriptors.h

@@ -211,7 +211,7 @@ class V8_EXPORT_PRIVATE CallInterfaceDescriptor {
   typedef CallInterfaceDescriptorData::Flags Flags;
 
   CallInterfaceDescriptor() : data_(nullptr) {}
-  virtual ~CallInterfaceDescriptor() {}
+  virtual ~CallInterfaceDescriptor() = default;
 
   CallInterfaceDescriptor(CallDescriptors::Key key)
       : data_(CallDescriptors::call_descriptor_data(key)) {}

src/isolate.cc

@@ -2265,10 +2265,6 @@ char* Isolate::RestoreThread(char* from) {
   return from + sizeof(ThreadLocalTop);
 }
 
-Isolate::ThreadDataTable::ThreadDataTable() : table_() {}
-
-Isolate::ThreadDataTable::~ThreadDataTable() {}
-
 void Isolate::ReleaseSharedPtrs() {
   while (managed_ptr_destructors_head_) {
     ManagedPtrDestructor* l = managed_ptr_destructors_head_;

src/isolate.h

@@ -1552,8 +1552,7 @@ class Isolate : private HiddenFactory {
 
   class ThreadDataTable {
    public:
-    ThreadDataTable();
-    ~ThreadDataTable();
+    ThreadDataTable() = default;
 
     PerIsolateThreadData* Lookup(ThreadId thread_id);
     void Insert(PerIsolateThreadData* data);

src/keys.cc

@@ -20,9 +20,6 @@
 namespace v8 {
 namespace internal {
 
-KeyAccumulator::~KeyAccumulator() {
-}
-
 namespace {
 
 static bool ContainsOnlyValidKeys(Handle<FixedArray> array) {

src/keys.h

@@ -37,7 +37,7 @@ class KeyAccumulator final {
   KeyAccumulator(Isolate* isolate, KeyCollectionMode mode,
                  PropertyFilter filter)
       : isolate_(isolate), mode_(mode), filter_(filter) {}
-  ~KeyAccumulator();
+  ~KeyAccumulator() = default;
 
   static MaybeHandle<FixedArray> GetKeys(
       Handle<JSReceiver> object, KeyCollectionMode mode, PropertyFilter filter,

src/libplatform/tracing/trace-buffer.cc

@@ -15,8 +15,6 @@ TraceBufferRingBuffer::TraceBufferRingBuffer(size_t max_chunks,
   chunks_.resize(max_chunks);
 }
 
-TraceBufferRingBuffer::~TraceBufferRingBuffer() {}
-
 TraceObject* TraceBufferRingBuffer::AddTraceEvent(uint64_t* handle) {
   base::LockGuard<base::Mutex> guard(&mutex_);
   if (is_empty_ || chunks_[chunk_index_]->IsFull()) {

src/libplatform/tracing/trace-buffer.h

@@ -18,7 +18,7 @@ namespace tracing {
 class TraceBufferRingBuffer : public TraceBuffer {
  public:
   TraceBufferRingBuffer(size_t max_chunks, TraceWriter* trace_writer);
-  ~TraceBufferRingBuffer() override;
+  ~TraceBufferRingBuffer() override = default;
 
   TraceObject* AddTraceEvent(uint64_t* handle) override;
   TraceObject* GetEventByHandle(uint64_t handle) override;

src/libplatform/tracing/tracing-controller.cc

@@ -40,7 +40,7 @@ const int g_num_builtin_categories = 3;
 // Skip default categories.
 v8::base::AtomicWord g_category_index = g_num_builtin_categories;
 
-TracingController::TracingController() {}
+TracingController::TracingController() = default;
 
 TracingController::~TracingController() {
   StopTracing();

src/log-utils.h

@@ -63,7 +63,7 @@ class Log {
     // Create a message builder starting from position 0.
     // This acquires the mutex in the log as well.
     explicit MessageBuilder(Log* log);
-    ~MessageBuilder() { }
+    ~MessageBuilder() = default;
 
     void AppendString(String* str,
                       base::Optional<int> length_limit = base::nullopt);