[heap] Add API function for checking if the heap limit was increased

src/heap/heap.h

 // 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.
 
 #ifndef V8_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 #include <map>
 
@@ skipping 938 matching lines @@
   }
 
   bool IsMemoryConstrainedDevice() {
     return max_old_generation_size_ <= kMaxOldSpaceSizeMediumMemoryDevice;
   }
 
   bool HighMemoryPressure() {
     return memory_pressure_level_.Value() != MemoryPressureLevel::kNone;
   }
 
-  void IncreaseHeapLimitForDebugging() {
+  size_t HeapLimitForDebugging() {
     const size_t kDebugHeapSizeFactor = 4;
     size_t max_limit = std::numeric_limits<size_t>::max() / 4;
+    return Min(max_limit,
+               initial_max_old_generation_size_ * kDebugHeapSizeFactor);
+  }
+
+  void IncreaseHeapLimitForDebugging() {
     max_old_generation_size_ =
-        Max(max_old_generation_size_,
-            Min(max_limit,
-                initial_max_old_generation_size_ * kDebugHeapSizeFactor));
+        Max(max_old_generation_size_, HeapLimitForDebugging());
   }
 
   void RestoreOriginalHeapLimit() {
     // Do not set the limit lower than the live size + some slack.
     size_t min_limit = SizeOfObjects() + SizeOfObjects() / 4;
     max_old_generation_size_ =
         Min(max_old_generation_size_,
             Max(initial_max_old_generation_size_, min_limit));
   }
 
+  bool IsHeapLimitIncreasedForDebugging() {
+    return max_old_generation_size_ == HeapLimitForDebugging();
+  }
+
   // ===========================================================================
   // Initialization. ===========================================================
   // ===========================================================================
 
   // Configure heap size in MB before setup. Return false if the heap has been
   // set up already.
   bool ConfigureHeap(size_t max_semi_space_size, size_t max_old_space_size,
                      size_t max_executable_size, size_t code_range_size);
   bool ConfigureHeapDefault();
 
@@ skipping 1690 matching lines @@
   friend class LargeObjectSpace;
   friend class NewSpace;
   friend class PagedSpace;
   DISALLOW_COPY_AND_ASSIGN(AllocationObserver);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_HEAP_H_