Implement wrapper tracing verifier

third_party/WebKit/Source/platform/heap/Heap.cpp

Index: third_party/WebKit/Source/platform/heap/Heap.cpp
diff --git a/third_party/WebKit/Source/platform/heap/Heap.cpp b/third_party/WebKit/Source/platform/heap/Heap.cpp
index 6156652cf87b70bd87ccab6fdab04eaecdfd74e6..b7bd6efe2438057fd856f5efea993984e45d7c93 100644
--- a/third_party/WebKit/Source/platform/heap/Heap.cpp
+++ b/third_party/WebKit/Source/platform/heap/Heap.cpp
@@ -32,6 +32,7 @@
 
 #include "base/sys_info.h"
 #include "platform/Histogram.h"
+#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/ScriptForbiddenScope.h"
 #include "platform/TraceEvent.h"
 #include "platform/heap/BlinkGCMemoryDumpProvider.h"
@@ -570,6 +571,10 @@ void ThreadHeap::collectGarbage(BlinkGC::StackState stackState, BlinkGC::GCType
     ThreadHeap::reportMemoryUsageHistogram();
     WTF::Partitions::reportMemoryUsageHistogram();
 
+    if (RuntimeEnabledFeatures::traceWrappablesEnabled()) {
+        state->invalidateDeadObjectsInWrappersMarkingDeque();

[haraken, 2016/06/22 15:43:12]

Why do we need this change?

[Marcel Hlopko, 2016/06/23 09:09:13]

We don't. Git rebase hates me :)

+    }
+
     state->heap().postGC(gcType);
     state->heap().decommitCallbackStacks();
 }