Changed StackZone and ApiZone to be containers for Zone.

runtime/vm/growable_array.h

Index: runtime/vm/growable_array.h
diff --git a/runtime/vm/growable_array.h b/runtime/vm/growable_array.h
index 73792093aefdb159b99a3c0c948cae50f7679259..91c95c25d3c93e451aaa9ddc3b764918c7c9dcf9 100644
--- a/runtime/vm/growable_array.h
+++ b/runtime/vm/growable_array.h
@@ -123,10 +123,10 @@ class GrowableArray : public BaseGrowableArray<T, ValueObject> {
   explicit GrowableArray(int initial_capacity)
       : BaseGrowableArray<T, ValueObject>(
           initial_capacity,
-          Isolate::Current()->current_zone()->GetBaseZone()) {}
+          Isolate::Current()->current_zone()) {}
   GrowableArray()
       : BaseGrowableArray<T, ValueObject>(
-          Isolate::Current()->current_zone()->GetBaseZone()) {}
+          Isolate::Current()->current_zone()) {}
 };
 
 
@@ -136,10 +136,10 @@ class ZoneGrowableArray : public BaseGrowableArray<T, ZoneAllocated> {
   explicit ZoneGrowableArray(int initial_capacity)
       : BaseGrowableArray<T, ZoneAllocated>(
           initial_capacity,
-          Isolate::Current()->current_zone()->GetBaseZone()) {}
+          Isolate::Current()->current_zone()) {}
   ZoneGrowableArray() :
       BaseGrowableArray<T, ZoneAllocated>(
-          Isolate::Current()->current_zone()->GetBaseZone()) {}
+          Isolate::Current()->current_zone()) {}
 };
 
 }  // namespace dart