Make copyToVector() robust against conservative GCs.

third_party/WebKit/Source/wtf/HashCountedSet.h

Index: third_party/WebKit/Source/wtf/HashCountedSet.h
diff --git a/third_party/WebKit/Source/wtf/HashCountedSet.h b/third_party/WebKit/Source/wtf/HashCountedSet.h
index 58b55f02552960cea56d08d2417aa0e15f033819..b6a5048f67b7b306c2cee958d28a884a3e75ef00 100644
--- a/third_party/WebKit/Source/wtf/HashCountedSet.h
+++ b/third_party/WebKit/Source/wtf/HashCountedSet.h
@@ -130,7 +130,11 @@ inline void copyToVector(const HashCountedSet<T, U, V, W>& collection, VectorTyp
 {
     typedef typename HashCountedSet<T, U, V, W>::const_iterator iterator;
 
-    vector.resize(collection.size());
+    {
+        // Disallow GC across resize allocation, see crbug.com/568173
+        typename VectorType::GCForbiddenScope scope;
+        vector.resize(collection.size());
+    }
 
     iterator it = collection.begin();
     iterator end = collection.end();
@@ -143,7 +147,11 @@ inline void copyToVector(const HashCountedSet<Value, HashFunctions, Traits, Allo
 {
     typedef typename HashCountedSet<Value, HashFunctions, Traits, Allocator>::const_iterator iterator;
 
-    vector.resize(collection.size());
+    {
+        // Disallow GC across resize allocation, see crbug.com/568173
+        typename Vector<Value, inlineCapacity, VectorAllocator>::GCForbiddenScope scope;
+        vector.resize(collection.size());
+    }
 
     iterator it = collection.begin();
     iterator end = collection.end();