Remove NT_PLACE, it's not really used.

operator new(size_t size, void* buffer, sandbox::AllocationType type) just
returns buffer, which is what the default placement new operator does too.

No intended behavior change.

(The motivation is to get rid of the two "return NULL"s in
`operator delete(void* memory, sandbox::AllocationType type)`, as they are
undefined behavior.)

BUG=none

Review URL: https://codereview.chromium.org/544333002

Cr-Commit-Position: refs/heads/master@{#294119}

sandbox/win/src/resolver_32.cc

@@ -4,6 +4,10 @@
 
 #include "sandbox/win/src/resolver.h"
 
+// For placement new. This file must not depend on the CRT at runtime, but
+// placement operator new is inline.
+#include <new>
+
 #include "sandbox/win/src/sandbox_nt_util.h"
 
 namespace {
@@ -62,7 +66,7 @@ bool ResolverThunk::SetInternalThunk(void* storage, size_t storage_bytes,
   if (storage_bytes < sizeof(InternalThunk))
     return false;
 
-  InternalThunk* thunk = new(storage, NT_PLACE) InternalThunk;
+  InternalThunk* thunk = new(storage) InternalThunk;
 
 #pragma warning(push)
 #pragma warning(disable: 4311)

sandbox/win/src/resolver_64.cc

@@ -4,6 +4,10 @@
 
 #include "sandbox/win/src/resolver.h"
 
+// For placement new. This file must not depend on the CRT at runtime, but
+// placement operator new is inline.
+#include <new>
+
 #include "sandbox/win/src/sandbox_nt_util.h"
 
 namespace {
@@ -53,7 +57,7 @@ bool ResolverThunk::SetInternalThunk(void* storage, size_t storage_bytes,
   if (storage_bytes < sizeof(InternalThunk))
     return false;
 
-  InternalThunk* thunk = new(storage, NT_PLACE) InternalThunk;
+  InternalThunk* thunk = new(storage) InternalThunk;
   thunk->interceptor_function = reinterpret_cast<ULONG_PTR>(interceptor);
 
   return true;

sandbox/win/src/sandbox_nt_types.h

@@ -37,7 +37,6 @@ struct NtExports {
 // This is the value used for the ntdll level allocator.
 enum AllocationType {
   NT_ALLOC,
-  NT_PLACE,
   NT_PAGE
 };