Teach mapFill{X,Y}Position about initial values to individual background layers

Source/core/css/resolver/CSSToStyleMap.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 200 matching lines @@
         secondLength = Length();
     }
 
     b.setWidth(firstLength);
     b.setHeight(secondLength);
     layer->setSizeLength(b);
 }
 
 void CSSToStyleMap::mapFillXPosition(CSSPropertyID propertyID, FillLayer* layer, CSSValue* value) const
 {
+    if (value->isInitialValue()) {

[Julien - ping for review, 2014/01/10 13:37:03]

Shouldn't you also handle the keyword 'inherit' here too?

[davve, 2014/01/10 14:09:49]

Hm, I don't think so. The added code is for handling absent values in each
layer. You may not set 'inherit' in a way that may reach this code. All
'inherit' values should be handled further up in StyleBuilder::applyProperty,
unless I'm missing something.

+        layer->setXPosition(FillLayer::initialFillXPosition(layer->type()));
+        return;
+    }
+
     if (!value->isPrimitiveValue())
         return;
 
     CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value);
     Pair* pair = primitiveValue->getPairValue();
     if (pair) {
         ASSERT_UNUSED(propertyID, propertyID == CSSPropertyBackgroundPositionX || propertyID == CSSPropertyWebkitMaskPositionX);
         primitiveValue = pair->second();
     }
 
     Length length = primitiveValue->convertToLength<FixedConversion | PercentConversion>(cssToLengthConversionData());
 
     layer->setXPosition(length);
     if (pair)
         layer->setBackgroundXOrigin(*(pair->first()));
 }
 
 void CSSToStyleMap::mapFillYPosition(CSSPropertyID propertyID, FillLayer* layer, CSSValue* value) const
 {
+    if (value->isInitialValue()) {
+        layer->setYPosition(FillLayer::initialFillYPosition(layer->type()));
+        return;
+    }
+
     if (!value->isPrimitiveValue())
         return;
 
     CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value);
     Pair* pair = primitiveValue->getPairValue();
     if (pair) {
         ASSERT_UNUSED(propertyID, propertyID == CSSPropertyBackgroundPositionY || propertyID == CSSPropertyWebkitMaskPositionY);
         primitiveValue = pair->second();
     }
 
@@ skipping 396 matching lines @@
         verticalRule = SpaceImageRule;
         break;
     default: // CSSValueRepeat
         verticalRule = RepeatImageRule;
         break;
     }
     image.setVerticalRule(verticalRule);
 }
 
 };