Merge from Chromium at DEPS revision 257591

This commit was generated by merge_to_master.py.

Change-Id: I834f3ca85c1ef7ec2c1061847a3d92aa461da043
diff --git a/Source/core/css/Pair.h b/Source/core/css/Pair.h
index e36d8d4..5cafb53 100644
--- a/Source/core/css/Pair.h
+++ b/Source/core/css/Pair.h
@@ -33,7 +33,6 @@
 // border-radius and background-size, but (FIXME) border-spacing and background-position could be converted over to use
 // it (eliminating some extra -webkit- internal properties).
 class Pair FINAL : public RefCountedWillBeGarbageCollected<Pair> {
-    DECLARE_GC_INFO;
 public:
     enum IdenticalValuesPolicy { DropIdenticalValues, KeepIdenticalValues };
 
@@ -67,8 +66,8 @@
 
 private:
     Pair()
-        : m_first(0)
-        , m_second(0)
+        : m_first(nullptr)
+        , m_second(nullptr)
         , m_identicalValuesPolicy(DropIdenticalValues) { }
 
     Pair(PassRefPtrWillBeRawPtr<CSSPrimitiveValue> first, PassRefPtrWillBeRawPtr<CSSPrimitiveValue> second, IdenticalValuesPolicy identicalValuesPolicy)