Reduce boot-up memory use of V8.

test/cctest/test-mark-compact.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 508 matching lines @@
 
     line_start = position;
   }
   close(fd);
   return memory_use;
 }
 
 
 TEST(BootUpMemoryUse) {
   intptr_t initial_memory = MemoryInUse();
+  FLAG_crankshaft = false;  // Avoid flakiness.
   // Only Linux has the proc filesystem and only if it is mapped.  If it's not
   // there we just skip the test.
   if (initial_memory >= 0) {
     InitializeVM();
     intptr_t booted_memory = MemoryInUse();
-    CHECK_LE(booted_memory - initial_memory, 16 * 1024 * 1024);
+    if (sizeof(initial_memory) == 8) {
+      if (v8::internal::Snapshot::IsEnabled()) {
+        CHECK_LE(booted_memory - initial_memory, 4700 * 1024);  // 4640.
+      } else {
+        CHECK_LE(booted_memory - initial_memory, 4300 * 1024);  // 4276.
+      }
+    } else {
+      if (v8::internal::Snapshot::IsEnabled()) {
+        CHECK_LE(booted_memory - initial_memory, 3300 * 1024);  // 3276.
+      } else {
+        CHECK_LE(booted_memory - initial_memory, 3500 * 1024);  // 3416
+      }
+    }
   }
 }
 
 #endif  // __linux__ and !USE_SIMULATOR