Move StyleBoxData.h to a nested class in ComputedStyle.

third_party/WebKit/Source/core/style/ComputedStyle.h

Index: third_party/WebKit/Source/core/style/ComputedStyle.h
diff --git a/third_party/WebKit/Source/core/style/ComputedStyle.h b/third_party/WebKit/Source/core/style/ComputedStyle.h
index 90342759e0e5d6ae4ceaf73ec095d9f5234f190e..ff5b21027c65aa8bbe3b14fcbc4b3b4264e75330 100644
--- a/third_party/WebKit/Source/core/style/ComputedStyle.h
+++ b/third_party/WebKit/Source/core/style/ComputedStyle.h
@@ -37,7 +37,6 @@
 #include "core/style/LineClampValue.h"
 #include "core/style/NinePieceImage.h"
 #include "core/style/SVGComputedStyle.h"
-#include "core/style/StyleBoxData.h"
 #include "core/style/StyleContentAlignmentData.h"
 #include "core/style/StyleDeprecatedFlexibleBoxData.h"
 #include "core/style/StyleDifference.h"
@@ -181,6 +180,58 @@ class CORE_EXPORT ComputedStyle : public ComputedStyleBase,
   friend class StyleResolverState;
   friend class StyleResolver;
 
+ private:
+  class StyleBoxData : public RefCountedCopyable<StyleBoxData> {
+   public:
+    static PassRefPtr<StyleBoxData> Create() {
+      return AdoptRef(new StyleBoxData);
+    }
+    PassRefPtr<StyleBoxData> Copy() const {
+      return AdoptRef(new StyleBoxData(*this));
+    }
+
+    bool operator==(const StyleBoxData& other) const {
+      return width_ == other.width_ && height_ == other.height_ &&
+             min_width_ == other.min_width_ && max_width_ == other.max_width_ &&
+             min_height_ == other.min_height_ &&
+             max_height_ == other.max_height_ &&
+             vertical_align_length_ == other.vertical_align_length_ &&
+             z_index_ == other.z_index_ &&
+             has_auto_z_index_ == other.has_auto_z_index_ &&
+             box_sizing_ == other.box_sizing_ &&
+             box_decoration_break_ == other.box_decoration_break_;
+    }
+    bool operator!=(const StyleBoxData& o) const { return !(*this == o); }
+
+    Length width_;
+    Length height_;
+    Length min_width_;
+    Length max_width_;
+    Length min_height_;
+    Length max_height_;
+    Length vertical_align_length_;
+    int z_index_;
+    unsigned has_auto_z_index_ : 1;
+    unsigned box_sizing_ : 1;            // EBoxSizing
+    unsigned box_decoration_break_ : 1;  // EBoxDecorationBreak
+
+   private:
+    StyleBoxData()
+        : width_(Length()),
+          height_(Length()),
+          min_width_(Length()),
+          max_width_(Length(kMaxSizeNone)),
+          min_height_(Length()),
+          max_height_(Length(kMaxSizeNone)),
+          z_index_(0),
+          has_auto_z_index_(static_cast<unsigned>(true)),
+          box_sizing_(static_cast<unsigned>(EBoxSizing::kContentBox)),
+          box_decoration_break_(
+              static_cast<unsigned>(EBoxDecorationBreak::kSlice)) {}
+
+    StyleBoxData(const StyleBoxData&) = default;
+  };
+
  protected:
   // non-inherited attributes
   DataRef<StyleBoxData> box_data_;