Add a ResourceConstraint for the embedder to specify that V8 is running on a memory constrained dev…

src/isolate.h

 // 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 1110 matching lines @@
   FunctionEntryHook function_entry_hook() { return function_entry_hook_; }
   void set_function_entry_hook(FunctionEntryHook function_entry_hook) {
     function_entry_hook_ = function_entry_hook;
   }
 
   void* stress_deopt_count_address() { return &stress_deopt_count_; }
 
   // Given an address occupied by a live code object, return that object.
   Object* FindCodeObject(Address a);
 
+  bool is_memory_constrained() const {
+    return is_memory_constrained_;
+  }
+  void set_is_memory_constrained(bool value) {
+    is_memory_constrained_ = value;
+  }
+
  private:
   Isolate();
 
   friend struct GlobalState;
   friend struct InitializeGlobalState;
 
   enum State {
     UNINITIALIZED,    // Some components may not have been allocated.
     INITIALIZED       // All components are fully initialized.
   };
@@ skipping 156 matching lines @@
   unibrow::Mapping<unibrow::CanonicalizationRange> jsregexp_canonrange_;
   ConsStringIteratorOp objects_string_compare_iterator_a_;
   ConsStringIteratorOp objects_string_compare_iterator_b_;
   StaticResource<ConsStringIteratorOp> objects_string_iterator_;
   unibrow::Mapping<unibrow::Ecma262Canonicalize>
       regexp_macro_assembler_canonicalize_;
   RegExpStack* regexp_stack_;
   DateCache* date_cache_;
   unibrow::Mapping<unibrow::Ecma262Canonicalize> interp_canonicalize_mapping_;
   CodeStubInterfaceDescriptor* code_stub_interface_descriptors_;
+  bool is_memory_constrained_;
 
   // True if fatal error has been signaled for this isolate.
   bool has_fatal_error_;
 
   // True if we are using the Crankshaft optimizing compiler.
   bool use_crankshaft_;
 
   // True if this isolate was initialized from a snapshot.
   bool initialized_from_snapshot_;
 
@@ skipping 208 matching lines @@
 
 // Mark the native context with out of memory.
 inline void Context::mark_out_of_memory() {
   native_context()->set_out_of_memory(HEAP->true_value());
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_