Add support for the object-position CSS property.

Source/core/css/CSSComputedStyleDeclaration.cpp

Index: Source/core/css/CSSComputedStyleDeclaration.cpp
diff --git a/Source/core/css/CSSComputedStyleDeclaration.cpp b/Source/core/css/CSSComputedStyleDeclaration.cpp
index dd2e82d38908db2c89904c793b053b3e464b3a1c..7ea36ea224f60fe8f2f654855b747ba34485feb1 100644
--- a/Source/core/css/CSSComputedStyleDeclaration.cpp
+++ b/Source/core/css/CSSComputedStyleDeclaration.cpp
@@ -156,6 +156,8 @@ static const CSSPropertyID staticComputableProperties[] = {
     CSSPropertyMinHeight,
     CSSPropertyMinWidth,
     CSSPropertyMixBlendMode,
+    CSSPropertyObjectFit,
+    CSSPropertyObjectPosition,
     CSSPropertyOpacity,
     CSSPropertyOrphans,
     CSSPropertyOutlineColor,
@@ -521,7 +523,7 @@ static PassRefPtr<CSSValue> valueForNinePieceImageRepeat(const NinePieceImage& i
         verticalRepeat = horizontalRepeat;
     else
         verticalRepeat = cssValuePool().createIdentifierValue(valueForRepeatRule(image.verticalRule()));
-    return cssValuePool().createValue(Pair::create(horizontalRepeat.release(), verticalRepeat.release()));
+    return cssValuePool().createValue(Pair::create(horizontalRepeat.release(), verticalRepeat.release(), Pair::DropIdenticalValues));
 }
 
 static PassRefPtr<CSSValue> valueForNinePieceImage(const NinePieceImage& image, const RenderStyle* style)
@@ -2183,6 +2185,12 @@ PassRefPtr<CSSValue> CSSComputedStyleDeclaration::getPropertyCSSValue(CSSPropert
             return zoomAdjustedPixelValueForLength(style->minWidth(), style.get());
         case CSSPropertyObjectFit:
             return cssValuePool().createValue(style->objectFit());
+        case CSSPropertyObjectPosition:
+            return cssValuePool().createValue(
+                Pair::create(
+                    cssValuePool().createValue(style->objectPosition().x()),
+                    cssValuePool().createValue(style->objectPosition().y()),
+                    Pair::KeepIdenticalValues));
         case CSSPropertyOpacity:
             return cssValuePool().createValue(style->opacity(), CSSPrimitiveValue::CSS_NUMBER);
         case CSSPropertyOrphans: