Bug 1321885 - Add Max() and Min() methods to TimeDuration. r=froydnj

MozReview-Commit-ID: 4WvRa3ZSrmP

--HG--
extra : rebase_source : d7433ab7cdb949194e494568f0bf94b91639e27e
extra : source : bac442a609767fbb21b266dbd719d6eb968fbf3d

mozglue/misc/TimeStamp.h

@@ -8,6 +8,7 @@
 #define mozilla_TimeStamp_h
 
 #include <stdint.h>
+#include <algorithm>  // for std::min, std::max
 #include "mozilla/Assertions.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/FloatingPoint.h"
@@ -175,6 +176,17 @@ public:
     return FromTicks(ticks);
   }
 
+  static BaseTimeDuration Max(const BaseTimeDuration& aA,
+                              const BaseTimeDuration& aB)
+  {
+    return FromTicks(std::max(aA.mValue, aB.mValue));
+  }
+  static BaseTimeDuration Min(const BaseTimeDuration& aA,
+                              const BaseTimeDuration& aB)
+  {
+    return FromTicks(std::min(aA.mValue, aB.mValue));
+  }
+
 private:
   // Block double multiplier (slower, imprecise if long duration) - Bug 853398.
   // If required, use MultDouble explicitly and with care.