[heap] Reland prepare code for smaller large object allocation limit than max allocatable memory.

test/cctest/test-api.cc

 // Copyright 2012 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 6529 matching lines @@
       a->Set(v8_str("x"), b);
       b->Set(v8_str("x"), a);
     }
     if (global_gc) {
       CcTest::heap()->CollectAllGarbage();
     } else {
       CcTest::heap()->CollectGarbage(i::NEW_SPACE);
     }
     // We are relying on this creating a big flag array and reserving the space
     // up front.
-    v8::Handle<Value> big_array = CompileRun("new Array(50000)");
+    v8::Handle<Value> big_array = CompileRun("new Array(5000)");
     a->Set(v8_str("y"), big_array);
     big_heap_size = CcTest::heap()->SizeOfObjects();
   }
 
   object_a.flag = false;
   object_b.flag = false;
   object_a.handle.SetWeak(&object_a, &SetFlag,
                           v8::WeakCallbackType::kParameter);
   object_b.handle.SetWeak(&object_b, &SetFlag,
                           v8::WeakCallbackType::kParameter);
   CHECK(!object_b.handle.IsIndependent());
   object_a.handle.MarkIndependent();
   object_b.handle.MarkIndependent();
   CHECK(object_b.handle.IsIndependent());
   if (global_gc) {
     CcTest::heap()->CollectAllGarbage();
   } else {
     CcTest::heap()->CollectGarbage(i::NEW_SPACE);
   }
   // A single GC should be enough to reclaim the memory, since we are using
   // phantom handles.
-  CHECK_LT(CcTest::heap()->SizeOfObjects(), big_heap_size - 200000);
+  CHECK_LT(CcTest::heap()->SizeOfObjects(), big_heap_size - 20000);
   CHECK(object_a.flag);
   CHECK(object_b.flag);
 }
 
 
 TEST(IndependentWeakHandle) {
   IndependentWeakHandle(false, false);
   IndependentWeakHandle(false, true);
   IndependentWeakHandle(true, false);
   IndependentWeakHandle(true, true);
@@ skipping 15310 matching lines @@
   ExpectTrue("object[Symbol.isConcatSpreadable]");
 
   // If access check fails, the value of @@isConcatSpreadable is ignored
   allowed_access = false;
   CompileRun("var result = [].concat(object)");
   ExpectTrue("Array.isArray(result)");
   ExpectTrue("result[0] === object");
   ExpectTrue("result.length === 1");
   ExpectTrue("object[Symbol.isConcatSpreadable] === undefined");
 }