[heap] Guard against re-entering GC on external memory change.

src/api.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/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 8132 matching lines @@
 
 
 void Isolate::ReportExternalAllocationLimitReached() {
   i::Heap* heap = reinterpret_cast<i::Isolate*>(this)->heap();
   if (heap->gc_state() != i::Heap::NOT_IN_GC) return;
   heap->ReportExternalMemoryPressure();
 }
 
 void Isolate::CheckMemoryPressure() {
   i::Heap* heap = reinterpret_cast<i::Isolate*>(this)->heap();
+  if (heap->gc_state() != i::Heap::NOT_IN_GC) return;
   heap->CheckMemoryPressure();
 }
 
 HeapProfiler* Isolate::GetHeapProfiler() {
   i::HeapProfiler* heap_profiler =
       reinterpret_cast<i::Isolate*>(this)->heap_profiler();
   return reinterpret_cast<HeapProfiler*>(heap_profiler);
 }
 
 
@@ skipping 2348 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8