Make NGFragment to own NGPhysicalFragment

third_party/WebKit/Source/core/layout/ng/ng_physical_fragment_base.h

Index: third_party/WebKit/Source/core/layout/ng/ng_physical_fragment_base.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_physical_fragment_base.h b/third_party/WebKit/Source/core/layout/ng/ng_physical_fragment_base.h
index 0a5000af6c6d7df907ec1c9a2277159f4df624f4..0d51d27c82d19b31efe7b06232c9af1940bb78bf 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_physical_fragment_base.h
+++ b/third_party/WebKit/Source/core/layout/ng/ng_physical_fragment_base.h
@@ -21,8 +21,7 @@ namespace blink {
 // Layout code should only access output layout information through the
 // NGFragmentBase classes which transforms information into the logical
 // coordinate system.
-class CORE_EXPORT NGPhysicalFragmentBase
-    : public GarbageCollected<NGPhysicalFragmentBase> {
+class CORE_EXPORT NGPhysicalFragmentBase {
  public:
   enum NGFragmentType { FragmentBox = 0, FragmentText = 1 };
 
@@ -61,9 +60,6 @@ class CORE_EXPORT NGPhysicalFragmentBase
 
   NGMarginStrut MarginStrut() const { return margin_strut_; }
 
-  DEFINE_INLINE_TRACE_AFTER_DISPATCH() {}
-  DECLARE_TRACE();
-
  protected:
   NGPhysicalFragmentBase(NGPhysicalSize size,
                          NGPhysicalSize overflow,