blink: Add backdrop-filter support

Source/core/css/ComputedStyleCSSValueMapping.cpp

 /*
  * Copyright (C) 2004 Zack Rusin <zack@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2011 Sencha, Inc. All rights reserved.
  * Copyright (C) 2015 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ skipping 1220 matching lines @@
     if (!shadowList)
         return cssValuePool().createIdentifierValue(CSSValueNone);
 
     RefPtrWillBeRawPtr<CSSValueList> list = CSSValueList::createCommaSeparated();
     size_t shadowCount = shadowList->shadows().size();
     for (size_t i = 0; i < shadowCount; ++i)
         list->append(valueForShadowData(shadowList->shadows()[i], style, useSpread));
     return list.release();
 }
 
-PassRefPtrWillBeRawPtr<CSSValue> ComputedStyleCSSValueMapping::valueForFilter(const ComputedStyle& style)
+PassRefPtrWillBeRawPtr<CSSValue> ComputedStyleCSSValueMapping::valueForFilter(const ComputedStyle& style, const FilterOperations& filterOperations)
 {
-    if (style.filter().operations().isEmpty())
+    if (filterOperations.operations().isEmpty())
         return cssValuePool().createIdentifierValue(CSSValueNone);
 
     RefPtrWillBeRawPtr<CSSValueList> list = CSSValueList::createSpaceSeparated();
 
     RefPtrWillBeRawPtr<CSSFunctionValue> filterValue = nullptr;
 
-    for (const auto& operation : style.filter().operations()) {
+    for (const auto& operation : filterOperations.operations()) {
         FilterOperation* filterOperation = operation.get();
         switch (filterOperation->type()) {
         case FilterOperation::REFERENCE:
             filterValue = CSSFunctionValue::create(CSSValueUrl);
             filterValue->append(cssValuePool().createValue(toReferenceFilterOperation(filterOperation)->url(), CSSPrimitiveValue::UnitType::CustomIdentifier));
             break;
         case FilterOperation::GRAYSCALE:
             filterValue = CSSFunctionValue::create(CSSValueGrayscale);
             filterValue->append(cssValuePool().createValue(toBasicColorMatrixFilterOperation(filterOperation)->amount(), CSSPrimitiveValue::UnitType::Number));
             break;
@@ skipping 1082 matching lines @@
                 return CSSPrimitiveValue::create(toReferenceClipPathOperation(operation)->url(), CSSPrimitiveValue::UnitType::URI);
         }
         return cssValuePool().createIdentifierValue(CSSValueNone);
     case CSSPropertyShapeMargin:
         return cssValuePool().createValue(style.shapeMargin(), style);
     case CSSPropertyShapeImageThreshold:
         return cssValuePool().createValue(style.shapeImageThreshold(), CSSPrimitiveValue::UnitType::Number);
     case CSSPropertyShapeOutside:
         return valueForShape(style, style.shapeOutside());
     case CSSPropertyWebkitFilter:
-        return valueForFilter(style);
+        return valueForFilter(style, style.filter());
+    case CSSPropertyBackdropFilter:
+        return valueForFilter(style, style.backdropFilter());
     case CSSPropertyMixBlendMode:
         return cssValuePool().createValue(style.blendMode());
 
     case CSSPropertyBackgroundBlendMode: {
         RefPtrWillBeRawPtr<CSSValueList> list = CSSValueList::createCommaSeparated();
         for (const FillLayer* currLayer = &style.backgroundLayers(); currLayer; currLayer = currLayer->next())
             list->append(cssValuePool().createValue(currLayer->blendMode()));
         return list.release();
     }
     case CSSPropertyBackground:
@@ skipping 325 matching lines @@
     case CSSPropertyAll:
         return nullptr;
     default:
         break;
     }
     ASSERT_NOT_REACHED();
     return nullptr;
 }
 
 }