Use a different GCCallbackFlag for GCs triggered by CollectAllAvailableGarbage

include/v8.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.
 
 /** \mainpage V8 API Reference Guide
  *
  * V8 is Google's open source JavaScript engine.
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
@@ skipping 5072 matching lines @@
  */
 enum GCType {
   kGCTypeScavenge = 1 << 0,
   kGCTypeMarkSweepCompact = 1 << 1,
   kGCTypeIncrementalMarking = 1 << 2,
   kGCTypeProcessWeakCallbacks = 1 << 3,
   kGCTypeAll = kGCTypeScavenge | kGCTypeMarkSweepCompact |
                kGCTypeIncrementalMarking | kGCTypeProcessWeakCallbacks
 };
 
+/**
+ * GCCallbackFlags is used to notify additional information about the GC
+ * callback.
+ *   - kGCCallbackFlagConstructRetainedObjectInfos: The GC callback is for
+ *     constructing retained object infos.
+ *   - kGCCallbackFlagForced: The GC callback is for a forced GC.
+ *   - kGCCallbackFlagSynchronousPhantomCallbackProcessing: The GC callback
+ *     is called synchronously without getting posted to an idle task.
+ *   - kGCCallbackFlagCollectAllAvailableGarbage: The GC callback is called
+ *     in a phase where V8 is trying to collect all available garbage
+ *     (e.g., handling a low memory notification).
+ */
 enum GCCallbackFlags {
   kNoGCCallbackFlags = 0,
   kGCCallbackFlagConstructRetainedObjectInfos = 1 << 1,
   kGCCallbackFlagForced = 1 << 2,
-  kGCCallbackFlagSynchronousPhantomCallbackProcessing = 1 << 3
+  kGCCallbackFlagSynchronousPhantomCallbackProcessing = 1 << 3,
+  kGCCallbackFlagCollectAllAvailableGarbage = 1 << 4,
 };
 
 typedef void (*GCCallback)(GCType type, GCCallbackFlags flags);
 
 typedef void (*InterruptCallback)(Isolate* isolate, void* data);
 
 
 /**
  * Collection of V8 heap information.
  *
@@ skipping 3485 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // INCLUDE_V8_H_