Add Chromium-style TimeDelta, Time and TimeTicks classes, and a new ElapsedTimer class.

src/lithium-allocator.cc

Index: src/lithium-allocator.cc
diff --git a/src/lithium-allocator.cc b/src/lithium-allocator.cc
index 2e2f802558c4a02606033a353e8356f51775b892..3c5abd19846d0ec018ab9c4947b1f84b17292bce 100644
--- a/src/lithium-allocator.cc
+++ b/src/lithium-allocator.cc
@@ -2189,7 +2189,7 @@ LAllocatorPhase::~LAllocatorPhase() {
   if (FLAG_hydrogen_stats) {
     unsigned size = allocator_->zone()->allocation_size() -
                     allocator_zone_start_allocation_size_;
-    isolate()->GetHStatistics()->SaveTiming(name(), 0, size);
+    isolate()->GetHStatistics()->SaveTiming(name(), TimeDelta(), size);
   }
 
   if (ShouldProduceTraceOutput()) {