Bug 1312086 - part 1 - pull the TimeStamp'd ConditionVariable::wait_for into platform-independent code; r=fitzgen

The implementation is exactly the same for both the Windows and Posix
implementations.  There's no need for the code duplication.

js/src/threading/ConditionVariable.h

@@ -63,7 +63,9 @@ public:
   // independent of system clock changes. While insulated from clock changes,
   // this API is succeptible to the issues discussed above wait_for.
   CVStatus wait_until(UniqueLock<Mutex>& lock,
-                      const mozilla::TimeStamp& abs_time);
+                      const mozilla::TimeStamp& abs_time) {
+    return wait_for(lock, abs_time - mozilla::TimeStamp::Now());
+  }
 
   // As with |wait_until|, block the current thread of execution until woken
   // from another thread, or the given absolute time is reached. This method

js/src/threading/posix/ConditionVariable.cpp

@@ -119,13 +119,6 @@ js::ConditionVariable::wait(UniqueLock<Mutex>& lock)
   MOZ_RELEASE_ASSERT(r == 0);
 }
 
-js::CVStatus
-js::ConditionVariable::wait_until(UniqueLock<Mutex>& lock,
-                                  const TimeStamp& abs_time)
-{
-  return wait_for(lock, abs_time - TimeStamp::Now());
-}
-
 js::CVStatus
 js::ConditionVariable::wait_for(UniqueLock<Mutex>& lock,
                                 const TimeDuration& a_rel_time)

js/src/threading/windows/ConditionVariable.cpp

@@ -59,13 +59,6 @@ js::ConditionVariable::wait(UniqueLock<Mutex>& lock)
   MOZ_RELEASE_ASSERT(r);
 }
 
-js::CVStatus
-js::ConditionVariable::wait_until(UniqueLock<Mutex>& lock,
-                                  const mozilla::TimeStamp& abs_time)
-{
-  return wait_for(lock, abs_time - mozilla::TimeStamp::Now());
-}
-
 js::CVStatus
 js::ConditionVariable::wait_for(UniqueLock<Mutex>& lock,
                                 const mozilla::TimeDuration& rel_time)