[object-stats] Split zone stats tracing into separate flag

Bug: v8:7266
Change-Id: I0983ec2db72e7013eb28e20370e13be282d0da39
Reviewed-on: https://chromium-review.googlesource.com/860377Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50484}

src/flag-definitions.h

@@ -665,6 +665,7 @@ DEFINE_BOOL(track_gc_object_stats, false,
             "track object counts and memory usage")
 DEFINE_BOOL(trace_gc_object_stats, false,
             "trace object counts and memory usage")
+DEFINE_BOOL(trace_zone_stats, false, "trace zone memory usage")
 DEFINE_BOOL(track_retaining_path, false,
             "enable support for tracking retaining path")
 DEFINE_BOOL(concurrent_array_buffer_freeing, true,

src/isolate.cc

@@ -2482,9 +2482,9 @@ Isolate::Isolate(bool enable_serializer)
       descriptor_lookup_cache_(nullptr),
       handle_scope_implementer_(nullptr),
       unicode_cache_(nullptr),
-      allocator_(FLAG_trace_gc_object_stats ? new VerboseAccountingAllocator(
-                                                  &heap_, 256 * KB, 128 * KB)
-                                            : new AccountingAllocator()),
+      allocator_(FLAG_trace_zone_stats ? new VerboseAccountingAllocator(
+                                             &heap_, 256 * KB, 128 * KB)
+                                       : new AccountingAllocator()),
       inner_pointer_to_code_cache_(nullptr),
       global_handles_(nullptr),
       eternal_handles_(nullptr),