Always adjust amount of external memory when change is reported.

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 15181 matching lines @@
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope outer(isolate);
   v8::Local<Context> env(Context::New(isolate));
   CHECK(!env.IsEmpty());
   const int64_t kSize = 1024*1024;
   int64_t baseline = isolate->AdjustAmountOfExternalAllocatedMemory(0);
   CHECK_EQ(baseline + kSize,
            isolate->AdjustAmountOfExternalAllocatedMemory(kSize));
   CHECK_EQ(baseline,
            isolate->AdjustAmountOfExternalAllocatedMemory(-kSize));
+  const int64_t kTriggerGCSize =
+      v8::internal::Internals::kExternalAllocationLimit + 1;
+  CHECK_EQ(baseline + kTriggerGCSize,
+           isolate->AdjustAmountOfExternalAllocatedMemory(kTriggerGCSize));
+  CHECK_EQ(baseline,
+           isolate->AdjustAmountOfExternalAllocatedMemory(-kTriggerGCSize));
 }
 
 
 // Regression test for issue 54, object templates with internal fields
 // but no accessors or interceptors did not get their internal field
 // count set on instances.
 THREADED_TEST(Regress54) {
   LocalContext context;
   v8::Isolate* isolate = context->GetIsolate();
   v8::HandleScope outer(isolate);
@@ skipping 9504 matching lines @@
                    "bar2.js");
 }
 
 
 TEST(StreamingScriptWithSourceMappingURLInTheMiddle) {
   const char* chunks[] = {"function foo() { ret", "urn 13; }\n//#",
                           " sourceMappingURL=bar2.js\n", "foo();", NULL};
   RunStreamingTest(chunks, v8::ScriptCompiler::StreamedSource::UTF8, true, NULL,
                    "bar2.js");
 }