[heap, debugger] Introduce out-of-memory listener for debugger.

src/debug/debug-interface.h

 // Copyright 2016 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_DEBUG_DEBUG_INTERFACE_H_
 #define V8_DEBUG_DEBUG_INTERFACE_H_
 
 #include "include/v8-debug.h"
 #include "include/v8-util.h"
 #include "include/v8.h"
@@ skipping 121 matching lines @@
   StepNext = 1,  // Step to the next statement in the current function.
   StepIn = 2,    // Step into new functions invoked or the next statement
                  // in the current function.
   StepFrame = 3  // Step into a new frame or return to previous frame.
 };
 
 void PrepareStep(Isolate* isolate, StepAction action);
 void ClearStepping(Isolate* isolate);
 
 /**
+ * Out-of-memory callback function.
+ * The function is invoked when the heap size is close to the hard limit.
+ *
+ * \param data the parameter provided during callback installation.
+ */
+typedef void (*OutOfMemoryCallback)(void* data);
+void SetOutOfMemoryCallback(Isolate* isolate, OutOfMemoryCallback callback,
+                            void* data);
+
+/**
  * Native wrapper around v8::internal::Script object.
  */
 class Script {
  public:
   v8::Isolate* GetIsolate() const;
 
   ScriptOriginOptions OriginOptions() const;
   bool WasCompiled() const;
   int Id() const;
   int LineOffset() const;
@@ skipping 37 matching lines @@
 
 void GetLoadedScripts(Isolate* isolate, PersistentValueVector<Script>& scripts);
 
 MaybeLocal<UnboundScript> CompileInspectorScript(Isolate* isolate,
                                                  Local<String> source);
 
 }  // namespace debug
 }  // namespace v8
 
 #endif  // V8_DEBUG_DEBUG_INTERFACE_H_