Support external startup data in V8.

src/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 4935 matching lines @@
   }
   if (FLAG_max_executable_size > 0) {
     max_executable_size_ = FLAG_max_executable_size * MB;
   }
 
   if (FLAG_stress_compaction) {
     // This will cause more frequent GCs when stressing.
     max_semi_space_size_ = Page::kPageSize;
   }
 
-  if (Snapshot::IsEnabled()) {
+  if (Snapshot::HaveASnapshotToStartFrom()) {
     // If we are using a snapshot we always reserve the default amount
     // of memory for each semispace because code in the snapshot has
     // write-barrier code that relies on the size and alignment of new
     // space.  We therefore cannot use a larger max semispace size
     // than the default reserved semispace size.
     if (max_semi_space_size_ > reserved_semispace_size_) {
       max_semi_space_size_ = reserved_semispace_size_;
       if (FLAG_trace_gc) {
         PrintPID("Max semi-space size cannot be more than %d kbytes\n",
                  reserved_semispace_size_ >> 10);
@@ skipping 1457 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal