Moved zones and zone related stuff in its own directory.

test/cctest/cctest.h

Index: test/cctest/cctest.h
diff --git a/test/cctest/cctest.h b/test/cctest/cctest.h
index 4ba609bbf46e66dbf797d0204c2c36baa84b02d7..d8fa871484d39b38081e0eeb2171cda93dbf40b4 100644
--- a/test/cctest/cctest.h
+++ b/test/cctest/cctest.h
@@ -32,9 +32,9 @@
 
 #include "include/libplatform/libplatform.h"
 #include "include/v8-debug.h"
-#include "src/base/accounting-allocator.h"
 #include "src/utils.h"
 #include "src/v8.h"
+#include "src/zone/accounting-allocator.h"
 
 namespace v8 {
 namespace base {
@@ -587,7 +587,7 @@ class HandleAndZoneScope : public InitializedHandleScope {
   i::Zone* main_zone() { return main_zone_.get(); }
 
  private:
-  v8::base::AccountingAllocator allocator_;
+  v8::internal::AccountingAllocator allocator_;
   std::unique_ptr<i::Zone> main_zone_;
 };