[cleanup] Refactor base to use default members.

Fixing clang-tidy warning.

Bug: v8:8015
Change-Id: Ifb940f40d4145a6074702a3d870242aeca625d96
Reviewed-on: https://chromium-review.googlesource.com/1224092Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Florian Sattler <sattlerf@google.com>
Cr-Commit-Position: refs/heads/master@{#55913}

src/base/debug/stack_trace.cc

@@ -21,7 +21,7 @@ StackTrace::StackTrace(const void* const* trace, size_t count) {
   count_ = count;
 }
 
-StackTrace::~StackTrace() {}
+StackTrace::~StackTrace() = default;
 
 const void* const* StackTrace::Addresses(size_t* count) const {
   *count = count_;

src/base/debug/stack_trace_posix.cc

@@ -125,7 +125,7 @@ class BacktraceOutputHandler {
   virtual void HandleOutput(const char* output) = 0;
 
  protected:
-  virtual ~BacktraceOutputHandler() {}
+  virtual ~BacktraceOutputHandler() = default;
 };
 
 #if HAVE_EXECINFO_H
@@ -266,7 +266,7 @@ void StackDumpSignalHandler(int signal, siginfo_t* info, void* void_context) {
 
 class PrintBacktraceOutputHandler : public BacktraceOutputHandler {
  public:
-  PrintBacktraceOutputHandler() {}
+  PrintBacktraceOutputHandler() = default;
 
   void HandleOutput(const char* output) override {
     // NOTE: This code MUST be async-signal safe (it's used by in-process

src/base/optional.h

@@ -123,7 +123,7 @@ class Optional {
  public:
   using value_type = T;
 
-  constexpr Optional() {}
+  constexpr Optional() = default;
 
   constexpr Optional(base::nullopt_t) {}  // NOLINT(runtime/explicit)
 

src/base/platform/platform-posix-time.h

@@ -15,7 +15,7 @@ class PosixDefaultTimezoneCache : public PosixTimezoneCache {
   const char* LocalTimezone(double time_ms) override;
   double LocalTimeOffset(double time_ms, bool is_utc) override;
 
-  ~PosixDefaultTimezoneCache() override {}
+  ~PosixDefaultTimezoneCache() override = default;
 };
 
 }  // namespace base

src/base/platform/platform-posix.h

@@ -15,7 +15,7 @@ class PosixTimezoneCache : public TimezoneCache {
  public:
   double DaylightSavingsOffset(double time_ms) override;
   void Clear() override {}
-  ~PosixTimezoneCache() override {}
+  ~PosixTimezoneCache() override = default;
 
  protected:
   static const int msPerSecond = 1000;

src/base/platform/platform.h

@@ -188,7 +188,7 @@ class V8_BASE_EXPORT OS {
 
   class V8_BASE_EXPORT MemoryMappedFile {
    public:
-    virtual ~MemoryMappedFile() {}
+    virtual ~MemoryMappedFile() = default;
     virtual void* memory() const = 0;
     virtual size_t size() const = 0;
 

src/base/platform/time.h

@@ -105,10 +105,7 @@ class V8_BASE_EXPORT TimeDelta final {
   static TimeDelta FromTimespec(struct timespec ts);
   struct timespec ToTimespec() const;
 
-  TimeDelta& operator=(const TimeDelta& other) {
-    delta_ = other.delta_;
-    return *this;
-  }
+  TimeDelta& operator=(const TimeDelta& other) = default;
 
   // Computations with other deltas.
   TimeDelta operator+(const TimeDelta& other) const {

src/base/safe_math.h

@@ -49,7 +49,7 @@ class CheckedNumeric {
  public:
   typedef T type;
 
-  CheckedNumeric() {}
+  CheckedNumeric() = default;
 
   // Copy constructor.
   template <typename Src>

src/base/timezone-cache.h

@@ -27,7 +27,7 @@ class TimezoneCache {
   virtual void Clear() = 0;
 
   // Called when tearing down the isolate
-  virtual ~TimezoneCache() {}
+  virtual ~TimezoneCache() = default;
 };
 
 }  // namespace base

test/unittests/base/functional-unittest.cc

@@ -44,7 +44,7 @@ class FunctionalTest : public ::testing::Test {
  public:
   FunctionalTest()
       : rng_(GetRandomSeedFromFlag(::v8::internal::FLAG_random_seed)) {}
-  virtual ~FunctionalTest() {}
+  virtual ~FunctionalTest() = default;
 
   RandomNumberGenerator* rng() { return &rng_; }