V8 minor GC should not ignore hasPendingActivity

third_party/WebKit/Source/bindings/core/v8/V8GCController.cpp

 /*
  * Copyright (C) 2009 Google Inc. 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
@@ skipping 104 matching lines @@
 
         // MinorGC does not collect objects because it may be expensive to
         // update references during minorGC
         if (classId == WrapperTypeInfo::ObjectClassId) {
             v8::Persistent<v8::Object>::Cast(*value).MarkActive();
             return;
         }
 
         v8::Local<v8::Object> wrapper = v8::Local<v8::Object>::New(m_isolate, v8::Persistent<v8::Object>::Cast(*value));
         ASSERT(V8DOMWrapper::hasInternalFieldsSet(wrapper));
-        const WrapperTypeInfo* type = toWrapperTypeInfo(wrapper);

[sof, 2016/02/25 13:08:13]

You still need this, I think, but need to add marking to it (like there used to
be.) i.e., the hasPendingActivity() check below is only for image elements.

[haraken, 2016/02/25 13:58:37]

Ah, nice catch. HTMLMediaElement needs to be marked as well.

I'll update the CL.

-        if (type != npObjectTypeInfo() && toScriptWrappable(wrapper)->hasPendingActivity())
-            return;
-
         if (classId == WrapperTypeInfo::NodeClassId) {
             ASSERT(V8Node::hasInstance(wrapper, m_isolate));
             Node* node = V8Node::toImpl(wrapper);
             if (node->hasEventListeners()) {
                 v8::Persistent<v8::Object>::Cast(*value).MarkActive();
                 return;
             }
             // FIXME: Remove the special handling for image elements.
             // The same special handling is in V8GCController::opaqueRootForGC().
             // Maybe should image elements be active DOM nodes?
@@ skipping 346 matching lines @@
 
     DEFINE_THREAD_SAFE_STATIC_LOCAL(CustomCountHistogram, scanPendingActivityHistogram, new CustomCountHistogram("Blink.ScanPendingActivityDuration", 1, 1000, 50));
     double startTime = WTF::currentTimeMS();
     PendingActivityVisitor visitor(executionContext);
     toIsolate(executionContext)->VisitHandlesWithClassIds(&visitor);
     scanPendingActivityHistogram.count(static_cast<int>(WTF::currentTimeMS() - startTime));
     return visitor.pendingActivityFound();
 }
 
 } // namespace blink