[date] Refactor TimezoneCache to be separate from the OS

This refactoring is preparatory work to enable ICU to be the backend
for timezone information rather than system calls. In the process, a
bit of code duplication that was inserted in the Solaris port patch is
eliminated here among modern POSIX backends.

One possible performance downside of this patch is that it introduces
a virtual method call for operations which were previously not virtual
methods. However, a couple factors mitigate this effect:
- The DateCache minimizes the need for calls into the TimezoneCache
- These calls were already not very high performance, as they included
  a system call which requires an RPC to get out of the sandbox, and
  they are surrounded by C++ builtins, which require a JS to C++
  transition.
- A future transition to ICU, enabled by this refactoring, may improve
  performance by eliminating the system call.

BUG=v8:6031

Review-Url: https://codereview.chromium.org/2731463003
Cr-Commit-Position: refs/heads/master@{#43588}

BUILD.gn

@@ -2323,6 +2323,7 @@ v8_component("v8_libbase") {
     "src/base/safe_math_impl.h",
     "src/base/sys-info.cc",
     "src/base/sys-info.h",
+    "src/base/timezone-cache.h",
     "src/base/utils/random-number-generator.cc",
     "src/base/utils/random-number-generator.h",
   ]
@@ -2338,7 +2339,10 @@ v8_component("v8_libbase") {
   }
 
   if (is_posix) {
-    sources += [ "src/base/platform/platform-posix.cc" ]
+    sources += [
+      "src/base/platform/platform-posix.cc",
+      "src/base/platform/platform-posix.h",
+    ]
   }
 
   if (is_linux) {

src/base/platform/platform-aix.cc

@@ -29,9 +29,9 @@
 #undef MAP_TYPE
 
 #include "src/base/macros.h"
+#include "src/base/platform/platform-posix.h"
 #include "src/base/platform/platform.h"
 
-
 namespace v8 {
 namespace base {
 
@@ -42,8 +42,15 @@ static inline void* mmapHelper(size_t len, int prot, int flags, int fildes,
   return mmap(addr, len, prot, flags, fildes, off);
 }
 
+class AIXTimezoneCache : public PosixTimezoneCache {
+  const char* LocalTimezone(double time) override;
 
-const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
+  double LocalTimeOffset() override;
+
+  ~AIXTimezoneCache() override {}
+};
+
+const char* AIXTimezoneCache::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(floor(time / msPerSecond));
   struct tm tm;
@@ -52,8 +59,7 @@ const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
   return tzname[0];  // The location of the timezone string on AIX.
 }
 
-
-double OS::LocalTimeOffset(TimezoneCache* cache) {
+double AIXTimezoneCache::LocalTimeOffset() {
   // On AIX, struct tm does not contain a tm_gmtoff field.
   time_t utc = time(NULL);
   DCHECK(utc != -1);
@@ -63,6 +69,7 @@ double OS::LocalTimeOffset(TimezoneCache* cache) {
   return static_cast<double>((mktime(loc) - utc) * msPerSecond);
 }
 
+TimezoneCache* OS::CreateTimezoneCache() { return new AIXTimezoneCache(); }
 
 void* OS::Allocate(const size_t requested, size_t* allocated, bool executable) {
   const size_t msize = RoundUp(requested, getpagesize());

src/base/platform/platform-cygwin.cc

@@ -19,14 +19,22 @@
 #undef MAP_TYPE
 
 #include "src/base/macros.h"
+#include "src/base/platform/platform-posix.h"
 #include "src/base/platform/platform.h"
 #include "src/base/win32-headers.h"
 
 namespace v8 {
 namespace base {
 
+class CygwinTimezoneCache : public PosixTimezoneCache {
+  const char* LocalTimezone(double time) override;
 
-const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
+  double LocalTimeOffset() override;
+
+  ~CygwinTimezoneCache() override {}
+};
+
+const char* CygwinTimezoneCache::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
   struct tm tm;
@@ -35,8 +43,7 @@ const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
   return tzname[0];  // The location of the timezone string on Cygwin.
 }
 
-
-double OS::LocalTimeOffset(TimezoneCache* cache) {
+double CygwinTimezoneCache::LocalTimeOffset() {
   // On Cygwin, struct tm does not contain a tm_gmtoff field.
   time_t utc = time(NULL);
   DCHECK(utc != -1);

src/base/platform/platform-freebsd.cc

@@ -29,32 +29,13 @@
 #undef MAP_TYPE
 
 #include "src/base/macros.h"
+#include "src/base/platform/platform-posix.h"
 #include "src/base/platform/platform.h"
 
-
 namespace v8 {
 namespace base {
 
-
-const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
-  if (std::isnan(time)) return "";
-  time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
-  struct tm tm;
-  struct tm* t = localtime_r(&tv, &tm);
-  if (NULL == t) return "";
-  return t->tm_zone;
-}
-
-
-double OS::LocalTimeOffset(TimezoneCache* cache) {
-  time_t tv = time(NULL);
-  struct tm tm;
-  struct tm* t = localtime_r(&tv, &tm);
-  // tm_gmtoff includes any daylight savings offset, so subtract it.
-  return static_cast<double>(t->tm_gmtoff * msPerSecond -
-                             (t->tm_isdst > 0 ? 3600 * msPerSecond : 0));
-}
-
+TimezoneCache* OS::CreateTimezoneCache() { return new PosixTimezoneCache(); }
 
 void* OS::Allocate(const size_t requested,
                    size_t* allocated,

src/base/platform/platform-linux.cc

@@ -44,6 +44,7 @@
 #undef MAP_TYPE
 
 #include "src/base/macros.h"
+#include "src/base/platform/platform-posix.h"
 #include "src/base/platform/platform.h"
 
 namespace v8 {
@@ -91,23 +92,7 @@ bool OS::ArmUsingHardFloat() {
 
 #endif  // def __arm__
 
-const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
-  if (std::isnan(time)) return "";
-  time_t tv = static_cast<time_t>(std::floor(time / msPerSecond));
-  struct tm tm;
-  struct tm* t = localtime_r(&tv, &tm);
-  if (!t || !t->tm_zone) return "";
-  return t->tm_zone;
-}
-
-double OS::LocalTimeOffset(TimezoneCache* cache) {
-  time_t tv = time(NULL);
-  struct tm tm;
-  struct tm* t = localtime_r(&tv, &tm);
-  // tm_gmtoff includes any daylight savings offset, so subtract it.
-  return static_cast<double>(t->tm_gmtoff * msPerSecond -
-                             (t->tm_isdst > 0 ? 3600 * msPerSecond : 0));
-}
+TimezoneCache* OS::CreateTimezoneCache() { return new PosixTimezoneCache(); }
 
 void* OS::Allocate(const size_t requested, size_t* allocated,
                    bool is_executable) {

src/base/platform/platform-macos.cc

@@ -36,6 +36,7 @@
 #undef MAP_TYPE
 
 #include "src/base/macros.h"
+#include "src/base/platform/platform-posix.h"
 #include "src/base/platform/platform.h"
 
 
@@ -98,26 +99,7 @@ std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() {
 void OS::SignalCodeMovingGC() {
 }
 
-
-const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
-  if (std::isnan(time)) return "";
-  time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
-  struct tm tm;
-  struct tm* t = localtime_r(&tv, &tm);
-  if (NULL == t) return "";
-  return t->tm_zone;
-}
-
-
-double OS::LocalTimeOffset(TimezoneCache* cache) {
-  time_t tv = time(NULL);
-  struct tm tm;
-  struct tm* t = localtime_r(&tv, &tm);
-  // tm_gmtoff includes any daylight savings offset, so subtract it.
-  return static_cast<double>(t->tm_gmtoff * msPerSecond -
-                             (t->tm_isdst > 0 ? 3600 * msPerSecond : 0));
-}
-
+TimezoneCache* OS::CreateTimezoneCache() { return new PosixTimezoneCache(); }
 
 VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { }
 

src/base/platform/platform-openbsd.cc

@@ -27,32 +27,13 @@
 #undef MAP_TYPE
 
 #include "src/base/macros.h"
+#include "src/base/platform/platform-posix.h"
 #include "src/base/platform/platform.h"
 
-
 namespace v8 {
 namespace base {
 
-
-const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
-  if (std::isnan(time)) return "";
-  time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
-  struct tm tm;
-  struct tm* t = localtime_r(&tv, &tm);
-  if (NULL == t) return "";
-  return t->tm_zone;
-}
-
-
-double OS::LocalTimeOffset(TimezoneCache* cache) {
-  time_t tv = time(NULL);
-  struct tm tm;
-  struct tm* t = localtime_r(&tv, &tm);
-  // tm_gmtoff includes any daylight savings offset, so subtract it.
-  return static_cast<double>(t->tm_gmtoff * msPerSecond -
-                             (t->tm_isdst > 0 ? 3600 * msPerSecond : 0));
-}
-
+TimezoneCache* OS::CreateTimezoneCache() { return new PosixTimezoneCache(); }
 
 void* OS::Allocate(const size_t requested,
                    size_t* allocated,

src/base/platform/platform-posix.cc

@@ -37,6 +37,8 @@
 #include <cmath>
 #include <cstdlib>
 
+#include "src/base/platform/platform-posix.h"
+
 #include "src/base/lazy-instance.h"
 #include "src/base/macros.h"
 #include "src/base/platform/platform.h"
@@ -380,26 +382,25 @@ double OS::TimeCurrentMillis() {
   return Time::Now().ToJsTime();
 }
 
-
-class TimezoneCache {};
-
-
-TimezoneCache* OS::CreateTimezoneCache() {
-  return NULL;
+const char* PosixTimezoneCache::LocalTimezone(double time) {
+  if (std::isnan(time)) return "";
+  time_t tv = static_cast<time_t>(std::floor(time / msPerSecond));
+  struct tm tm;
+  struct tm* t = localtime_r(&tv, &tm);
+  if (!t || !t->tm_zone) return "";
+  return t->tm_zone;
 }
 
-
-void OS::DisposeTimezoneCache(TimezoneCache* cache) {
-  DCHECK(cache == NULL);
+double PosixTimezoneCache::LocalTimeOffset() {
+  time_t tv = time(NULL);
+  struct tm tm;
+  struct tm* t = localtime_r(&tv, &tm);
+  // tm_gmtoff includes any daylight savings offset, so subtract it.
+  return static_cast<double>(t->tm_gmtoff * msPerSecond -
+                             (t->tm_isdst > 0 ? 3600 * msPerSecond : 0));
 }
 
-
-void OS::ClearTimezoneCache(TimezoneCache* cache) {
-  DCHECK(cache == NULL);
-}
-
-
-double OS::DaylightSavingsOffset(double time, TimezoneCache*) {
+double PosixTimezoneCache::DaylightSavingsOffset(double time) {
   if (std::isnan(time)) return std::numeric_limits<double>::quiet_NaN();
   time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
   struct tm tm;

src/base/platform/platform-posix.h

@@ -0,0 +1,28 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BASE_PLATFORM_PLATFORM_POSIX_H_
+#define V8_BASE_PLATFORM_PLATFORM_POSIX_H_
+
+#include "src/base/timezone-cache.h"
+
+namespace v8 {
+namespace base {
+
+class PosixTimezoneCache : public TimezoneCache {
+ public:
+  const char* LocalTimezone(double time_ms) override;
+  double DaylightSavingsOffset(double time_ms) override;
+  double LocalTimeOffset() override;
+  void Clear() override {}
+  ~PosixTimezoneCache() override {}
+
+ protected:
+  static const int msPerSecond = 1000;
+};
+
+}  // namespace base
+}  // namespace v8
+
+#endif  // V8_BASE_PLATFORM_PLATFORM_POSIX_H_

src/base/platform/platform-qnx.cc

@@ -31,9 +31,9 @@
 #undef MAP_TYPE
 
 #include "src/base/macros.h"
+#include "src/base/platform/platform-posix.h"
 #include "src/base/platform/platform.h"
 
-
 namespace v8 {
 namespace base {
 
@@ -84,26 +84,7 @@ bool OS::ArmUsingHardFloat() {
 
 #endif  // __arm__
 
-
-const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
-  if (std::isnan(time)) return "";
-  time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
-  struct tm tm;
-  struct tm* t = localtime_r(&tv, &tm);
-  if (NULL == t) return "";
-  return t->tm_zone;
-}
-
-
-double OS::LocalTimeOffset(TimezoneCache* cache) {
-  time_t tv = time(NULL);
-  struct tm tm;
-  struct tm* t = localtime_r(&tv, &tm);
-  // tm_gmtoff includes any daylight savings offset, so subtract it.
-  return static_cast<double>(t->tm_gmtoff * msPerSecond -
-                             (t->tm_isdst > 0 ? 3600 * msPerSecond : 0));
-}
-
+TimezoneCache* OS::CreateTimezoneCache() { return new PosixTimezoneCache(); }
 
 void* OS::Allocate(const size_t requested,
                    size_t* allocated,

src/base/platform/platform-solaris.cc

@@ -28,14 +28,21 @@
 #undef MAP_TYPE
 
 #include "src/base/macros.h"
+#include "src/base/platform/platform-posix.h"
 #include "src/base/platform/platform.h"
 
-
 namespace v8 {
 namespace base {
 
+class SolarisTimezoneCache : public PosixTimezoneCache {
+  const char* LocalTimezone(double time) override;
 
-const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
+  double LocalTimeOffset() override;
+
+  ~SolarisTimezoneCache() override {}
+};
+
+const char* SolarisTimezoneCache::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
   struct tm tm;
@@ -44,12 +51,12 @@ const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
   return tzname[0];  // The location of the timezone string on Solaris.
 }
 
-
-double OS::LocalTimeOffset(TimezoneCache* cache) {
+double SolarisTimezoneCache::LocalTimeOffset() {
   tzset();
   return -static_cast<double>(timezone * msPerSecond);
 }
 
+TimezoneCache* OS::CreateTimezoneCache() { return new SolarisTimezoneCache(); }
 
 void* OS::Allocate(const size_t requested,
                    size_t* allocated,

src/base/platform/platform-win32.cc

@@ -24,9 +24,9 @@
 #include "src/base/macros.h"
 #include "src/base/platform/platform.h"
 #include "src/base/platform/time.h"
+#include "src/base/timezone-cache.h"
 #include "src/base/utils/random-number-generator.h"
 
-
 // Extra functions for MinGW. Most of these are the _s functions which are in
 // the Microsoft Visual Studio C++ CRT.
 #ifdef __MINGW32__
@@ -101,13 +101,19 @@ bool g_hard_abort = false;
 
 }  // namespace
 
-class TimezoneCache {
+class WindowsTimezoneCache : public TimezoneCache {
  public:
-  TimezoneCache() : initialized_(false) { }
+  WindowsTimezoneCache() : initialized_(false) {}
 
-  void Clear() {
-    initialized_ = false;
-  }
+  ~WindowsTimezoneCache() override {}
+
+  void Clear() override { initialized_ = false; }
+
+  const char* LocalTimezone(double time) override;
+
+  double LocalTimeOffset() override;
+
+  double DaylightSavingsOffset(double time) override;
 
   // Initialize timezone information. The timezone information is obtained from
   // windows. If we cannot get the timezone information we fall back to CET.
@@ -216,14 +222,14 @@ class Win32Time {
   // LocalOffset(CET) = 3600000 and LocalOffset(PST) = -28800000. This
   // routine also takes into account whether daylight saving is effect
   // at the time.
-  int64_t LocalOffset(TimezoneCache* cache);
+  int64_t LocalOffset(WindowsTimezoneCache* cache);
 
   // Returns the daylight savings time offset for the time in milliseconds.
-  int64_t DaylightSavingsOffset(TimezoneCache* cache);
+  int64_t DaylightSavingsOffset(WindowsTimezoneCache* cache);
 
   // Returns a string identifying the current timezone for the
   // timestamp taking into account daylight saving.
-  char* LocalTimezone(TimezoneCache* cache);
+  char* LocalTimezone(WindowsTimezoneCache* cache);
 
  private:
   // Constants for time conversion.
@@ -235,7 +241,7 @@ class Win32Time {
   static const bool kShortTzNames = false;
 
   // Return whether or not daylight savings time is in effect at this time.
-  bool InDST(TimezoneCache* cache);
+  bool InDST(WindowsTimezoneCache* cache);
 
   // Accessor for FILETIME representation.
   FILETIME& ft() { return time_.ft_; }
@@ -350,7 +356,7 @@ void Win32Time::SetToCurrentTime() {
 // Only times in the 32-bit Unix range may be passed to this function.
 // Also, adding the time-zone offset to the input must not overflow.
 // The function EquivalentTime() in date.js guarantees this.
-int64_t Win32Time::LocalOffset(TimezoneCache* cache) {
+int64_t Win32Time::LocalOffset(WindowsTimezoneCache* cache) {
   cache->InitializeIfNeeded();
 
   Win32Time rounded_to_second(*this);
@@ -384,7 +390,7 @@ int64_t Win32Time::LocalOffset(TimezoneCache* cache) {
 
 
 // Return whether or not daylight savings time is in effect at this time.
-bool Win32Time::InDST(TimezoneCache* cache) {
+bool Win32Time::InDST(WindowsTimezoneCache* cache) {
   cache->InitializeIfNeeded();
 
   // Determine if DST is in effect at the specified time.
@@ -409,14 +415,14 @@ bool Win32Time::InDST(TimezoneCache* cache) {
 
 
 // Return the daylight savings time offset for this time.
-int64_t Win32Time::DaylightSavingsOffset(TimezoneCache* cache) {
+int64_t Win32Time::DaylightSavingsOffset(WindowsTimezoneCache* cache) {
   return InDST(cache) ? 60 * kMsPerMinute : 0;
 }
 
 
 // Returns a string identifying the current timezone for the
 // timestamp taking into account daylight saving.
-char* Win32Time::LocalTimezone(TimezoneCache* cache) {
+char* Win32Time::LocalTimezone(WindowsTimezoneCache* cache) {
   // Return the standard or DST time zone name based on whether daylight
   // saving is in effect at the given time.
   return InDST(cache) ? cache->dst_tz_name_ : cache->std_tz_name_;
@@ -448,47 +454,30 @@ double OS::TimeCurrentMillis() {
   return Time::Now().ToJsTime();
 }
 
-
-TimezoneCache* OS::CreateTimezoneCache() {
-  return new TimezoneCache();
-}
-
-
-void OS::DisposeTimezoneCache(TimezoneCache* cache) {
-  delete cache;
-}
-
-
-void OS::ClearTimezoneCache(TimezoneCache* cache) {
-  cache->Clear();
-}
-
-
 // Returns a string identifying the current timezone taking into
 // account daylight saving.
-const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
-  return Win32Time(time).LocalTimezone(cache);
+const char* WindowsTimezoneCache::LocalTimezone(double time) {
+  return Win32Time(time).LocalTimezone(this);
 }
 
-
 // Returns the local time offset in milliseconds east of UTC without
 // taking daylight savings time into account.
-double OS::LocalTimeOffset(TimezoneCache* cache) {
+double WindowsTimezoneCache::LocalTimeOffset() {
   // Use current time, rounded to the millisecond.
-  Win32Time t(TimeCurrentMillis());
+  Win32Time t(OS::TimeCurrentMillis());
   // Time::LocalOffset inlcudes any daylight savings offset, so subtract it.
-  return static_cast<double>(t.LocalOffset(cache) -
-                             t.DaylightSavingsOffset(cache));
+  return static_cast<double>(t.LocalOffset(this) -
+                             t.DaylightSavingsOffset(this));
 }
 
-
 // Returns the daylight savings offset in milliseconds for the given
 // time.
-double OS::DaylightSavingsOffset(double time, TimezoneCache* cache) {
-  int64_t offset = Win32Time(time).DaylightSavingsOffset(cache);
+double WindowsTimezoneCache::DaylightSavingsOffset(double time) {
+  int64_t offset = Win32Time(time).DaylightSavingsOffset(this);
   return static_cast<double>(offset);
 }
 
+TimezoneCache* OS::CreateTimezoneCache() { return new WindowsTimezoneCache(); }
 
 int OS::GetLastError() {
   return ::GetLastError();

src/base/platform/platform.h

@@ -124,19 +124,6 @@ class V8_BASE_EXPORT OS {
   static double TimeCurrentMillis();
 
   static TimezoneCache* CreateTimezoneCache();
-  static void DisposeTimezoneCache(TimezoneCache* cache);
-  static void ClearTimezoneCache(TimezoneCache* cache);
-
-  // Returns a string identifying the current time zone. The
-  // timestamp is used for determining if DST is in effect.
-  static const char* LocalTimezone(double time, TimezoneCache* cache);
-
-  // Returns the local time offset in milliseconds east of UTC without
-  // taking daylight savings time into account.
-  static double LocalTimeOffset(TimezoneCache* cache);
-
-  // Returns the daylight savings offset for the given time.
-  static double DaylightSavingsOffset(double time, TimezoneCache* cache);
 
   // Returns last OS error.
   static int GetLastError();

src/base/timezone-cache.h

@@ -0,0 +1,38 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BASE_TIMEZONE_CACHE_H_
+#define V8_BASE_TIMEZONE_CACHE_H_
+
+namespace v8 {
+namespace base {
+
+class TimezoneCache {
+ public:
+  // Short name of the local timezone (e.g., EST)
+  virtual const char* LocalTimezone(double time_ms) = 0;
+
+  // ES #sec-daylight-saving-time-adjustment
+  // Daylight Saving Time Adjustment
+  virtual double DaylightSavingsOffset(double time_ms) = 0;
+
+  // ES #sec-local-time-zone-adjustment
+  // Local Time Zone Adjustment
+  //
+  // TODO(littledan): Make more accurate with another parameter along the
+  // lines of this spec change:
+  // https://github.com/tc39/ecma262/pull/778
+  virtual double LocalTimeOffset() = 0;
+
+  // Called when the local timezone changes
+  virtual void Clear() = 0;
+
+  // Called when tearing down the isolate
+  virtual ~TimezoneCache() {}
+};
+
+}  // namespace base
+}  // namespace v8
+
+#endif  // V8_BASE_TIMEZONE_CACHE_H_

src/date.cc

@@ -38,7 +38,7 @@ void DateCache::ResetDateCache() {
   after_ = &dst_[1];
   local_offset_ms_ = kInvalidLocalOffsetInMs;
   ymd_valid_ = false;
-  base::OS::ClearTimezoneCache(tz_cache_);
+  tz_cache_->Clear();
 }
 
 

src/date.h

@@ -7,9 +7,9 @@
 
 #include "src/allocation.h"
 #include "src/base/platform/platform.h"
+#include "src/base/timezone-cache.h"
 #include "src/globals.h"
 
-
 namespace v8 {
 namespace internal {
 
@@ -44,7 +44,7 @@ class DateCache {
   }
 
   virtual ~DateCache() {
-    base::OS::DisposeTimezoneCache(tz_cache_);
+    delete tz_cache_;
     tz_cache_ = NULL;
   }
 
@@ -93,7 +93,7 @@ class DateCache {
     if (time_ms < 0 || time_ms > kMaxEpochTimeInMs) {
       time_ms = EquivalentTime(time_ms);
     }
-    return base::OS::LocalTimezone(static_cast<double>(time_ms), tz_cache_);
+    return tz_cache_->LocalTimezone(static_cast<double>(time_ms));
   }
 
   // ECMA 262 - 15.9.5.26
@@ -204,12 +204,11 @@ class DateCache {
   // These functions are virtual so that we can override them when testing.
   virtual int GetDaylightSavingsOffsetFromOS(int64_t time_sec) {
     double time_ms = static_cast<double>(time_sec * 1000);
-    return static_cast<int>(
-        base::OS::DaylightSavingsOffset(time_ms, tz_cache_));
+    return static_cast<int>(tz_cache_->DaylightSavingsOffset(time_ms));
   }
 
   virtual int GetLocalOffsetFromOS() {
-    double offset = base::OS::LocalTimeOffset(tz_cache_);
+    double offset = tz_cache_->LocalTimeOffset();
     DCHECK(offset < kInvalidLocalOffsetInMs);
     return static_cast<int>(offset);
   }

src/v8.gyp

@@ -1873,6 +1873,7 @@
         'base/safe_math_impl.h',
         'base/sys-info.cc',
         'base/sys-info.h',
+        'base/timezone-cache.h',
         'base/utils/random-number-generator.cc',
         'base/utils/random-number-generator.h',
       ],
@@ -1913,6 +1914,7 @@
             'sources': [
               'base/debug/stack_trace_posix.cc',
               'base/platform/platform-linux.cc',
+              'base/platform/platform-posix.h',
               'base/platform/platform-posix.cc',
             ],
           }
@@ -1920,6 +1922,7 @@
         ['OS=="android"', {
             'sources': [
               'base/debug/stack_trace_android.cc',
+              'base/platform/platform-posix.h',
               'base/platform/platform-posix.cc',
             ],
             'link_settings': {
@@ -1975,6 +1978,7 @@
             },
             'sources': [
               'base/debug/stack_trace_posix.cc',
+              'base/platform/platform-posix.h',
               'base/platform/platform-posix.cc',
               'base/qnx-math.h'
             ],
@@ -2005,6 +2009,7 @@
             'sources': [
               'base/debug/stack_trace_posix.cc',
               'base/platform/platform-freebsd.cc',
+              'base/platform/platform-posix.h',
               'base/platform/platform-posix.cc',
             ],
           }
@@ -2016,6 +2021,7 @@
             ]},
             'sources': [
               'base/platform/platform-openbsd.cc',
+              'base/platform/platform-posix.h',
               'base/platform/platform-posix.cc'
             ],
           }
@@ -2028,6 +2034,7 @@
             'sources': [
               'base/debug/stack_trace_posix.cc',
               'base/platform/platform-openbsd.cc',
+              'base/platform/platform-posix.h',
               'base/platform/platform-posix.cc',
             ],
           }
@@ -2036,6 +2043,7 @@
           'sources': [
             'base/debug/stack_trace_posix.cc',
             'base/platform/platform-aix.cc',
+            'base/platform/platform-posix.h',
             'base/platform/platform-posix.cc'
           ]},
         ],
@@ -2047,6 +2055,7 @@
             'sources': [
               'base/debug/stack_trace_posix.cc',
               'base/platform/platform-solaris.cc',
+              'base/platform/platform-posix.h',
               'base/platform/platform-posix.cc',
             ],
           }
@@ -2055,6 +2064,7 @@
           'sources': [
             'base/debug/stack_trace_posix.cc',
             'base/platform/platform-macos.cc',
+            'base/platform/platform-posix.h',
             'base/platform/platform-posix.cc',
           ]},
         ],
@@ -2075,6 +2085,7 @@
                   'sources': [
                     'base/debug/stack_trace_posix.cc',
                     'base/platform/platform-cygwin.cc',
+                    'base/platform/platform-posix.h',
                     'base/platform/platform-posix.cc',
                   ],
                 }, {