Make Time functions go through the Platform layer.

include/v8-platform.h

Index: include/v8-platform.h
diff --git a/include/v8-platform.h b/include/v8-platform.h
index 75fddd59a873b75db0d05bd1e3fc733b1e1a9265..214c1e52eab0b011c2d5d9616dfcc752ab4f1849 100644
--- a/include/v8-platform.h
+++ b/include/v8-platform.h
@@ -77,6 +77,65 @@ class Platform {
    */
   virtual void CallOnForegroundThread(Isolate* isolate, Task* task) = 0;
 
+  /**
+   * The current time, represented as microseconds (s/1,000,000) since
+   * 00:00:00 UTC, January 1, 1970.
+   *
+   * This value can go backwards, if the system adjusts its clock.
+   */
+  virtual int64_t CurrentTime();
+
+  /**
+   * The current time, represented as microseconds (s/1,000,000) since
+   * 00:00:00 UTC, January 1, 1970.
+   *
+   * This function always uses system time so that there are no discrepancies
+   * between the returned time and system time even on virtual environments,
+   * including our test bot.
+   *
+   * This value can go backwards, if the system adjusts its clock.
+   *
+   * This function is used for timing sensitive unittests.
+   */
+  virtual int64_t CurrentTimeFromSystemTime();
+
+  /**
+   * An abstract time intended for use in measuring time durations, represented
+   * as microseconds.
+   *
+   * This is guaranteed not to decrease even if the computer clock goes
+   * backwards, but it may "stand still", for example if the computer is
+   * suspended.
+   *
+   * The resolution of this clock can be as low as 15ms, and it varies
+   * depending on hardware/operating system.
+   *
+   * This method never returns 0.
+   */
+  virtual int64_t TimeTicksNow();
+
+  /**
+   * An abstract time intended for use in measuring time durations, represented
+   * as microseconds.
+   *
+   * This is guaranteed not to decrease even if the computer clock goes
+   * backwards, but it may "stand still", for example if the computer is
+   * suspended.
+   *
+   * The implementation is hardware dependent and its return values may or may
+   * not have sub-millisecond resolution. THIS CALL IS GENERALLY MUCH MORE
+   * EXPENSIVE THAN TimeTicksNow() AND SHOULD ONLY BE USED WHEN IT IS REALLY
+   * NEEDED.
+   *
+   * This method never returns 0.
+   */
+  virtual int64_t TimeTicksHighResNow();
+
+  /**
+   * True if the TimeTicksHighResNow() returns values with high resolution.
+   */
+  virtual bool TimeTicksHasHighRes();
+
  protected:
   virtual ~Platform() {}
 };