Implement all shorthand 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 51c12ec281d94ec9f35dd6962c065bcaaffc99ef..cea6c07046071aa9957c9a26e403354762dcbede 100644
--- a/Source/core/css/CSSComputedStyleDeclaration.cpp
+++ b/Source/core/css/CSSComputedStyleDeclaration.cpp
@@ -2859,6 +2859,23 @@ PassRefPtrWillBeRawPtr<CSSValue> CSSComputedStyleDeclaration::getPropertyCSSValu
         case CSSPropertyPaintOrder:
         case CSSPropertyWritingMode:
             return getSVGPropertyCSSValue(propertyID, DoNotUpdateLayout);
+
+        case CSSPropertyAll:
+        {
+            // FIXME: need to support "unset".
+            bool isInitial = true;
+            bool isInherit = true;
+            for (unsigned i = 0; i < allShorthand().length() && (isInitial || isInherit); ++i) {
+                RefPtrWillBeRawPtr<CSSValue> value = getPropertyCSSValue(allShorthand().properties()[i], DoNotUpdateLayout);
+                isInitial = isInitial && value->isInitialValue();
+                isInherit = isInherit && value->isInheritedValue();

[esprehn, 2014/05/02 22:24:11]

What is this doing? This loop doesn't make sense to me.

[tasak, 2014/05/12 14:33:27]

I would like to see if all longhands have initial value or inherited value.
Since getPropertyCSSValue looks a little heavy, I check both initial and inherit
in the same loop.

+            }
+            if (isInitial)
+                return cssValuePool().createExplicitInitialValue();
+            if (isInherit)
+                return cssValuePool().createInheritedValue();
+            return nullptr;
+        }
     }
 
     logUnimplementedPropertyID(propertyID);