Reduce ephemeron stack size reservation.

third_party/WebKit/Source/platform/heap/BlinkGC.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BlinkGC_h
 #define BlinkGC_h
 
 // BlinkGC.h is a file that defines common things used by Blink GC.
 
+#include "platform/PlatformExport.h"
 #include "wtf/Allocator.h"
 
 namespace blink {
 
 class Visitor;
 
 #define PRINT_HEAP_STATS 0 // Enable this macro to print heap stats to stderr.
 
 using Address = uint8_t*;
 
@@ skipping 92 matching lines @@
 
     enum V8GCType {
         V8MinorGC,
         V8MajorGC,
     };
 };
 
 } // namespace blink
 
 #endif