Include what you use for the files zone*

src/zone.cc

Index: src/zone.cc
diff --git a/src/zone.cc b/src/zone.cc
index 2d14d137efddf6119c8dd24daf7b5d5b4490375a..0f810a0a4245c2019f424554584bd7d53fb3481c 100644
--- a/src/zone.cc
+++ b/src/zone.cc
@@ -25,10 +25,11 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#include "v8.h"
+#include <string.h>
 
+#include "allocation.h"

[Kevin Millikin (Chromium), 2012/01/30 09:25:45]

You are welcome to leave allocation.h out since it comes to us via zone-inl.h
(or put it in, I don't much care).

Please include headers in this order:

#include "v8.h"
#include "zone-inl.h"

#include <string.h>
#include "allocation.h"

The first block are those that (possibly) can't be reordered, and they are
intentionally not alphabetized.  v8.h is first because it contains all the
included that have circular dependencies included in just the right order.

[Yang, 2012/01/30 10:46:03]

Our presubmit script however says:
zone.cc:31:  Found C system header after other header. Should be: zone.h, c
system, c++ system, other.
I guess I'll move string.h to the top.

+#include "v8.h"
 #include "zone-inl.h"
-#include "splay-tree-inl.h"
 
 namespace v8 {
 namespace internal {