Adds filter support for offscreen canvas

third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp

Index: third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
diff --git a/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp b/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
index 552385189874a4ccf7d6b9cb6d5a2133d853753d..0f0747cec2edfc129e410c6267c5ef8a862b7ce2 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
+++ b/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp
@@ -28,6 +28,7 @@
 
 #include "core/css/BasicShapeFunctions.h"
 #include "core/css/CSSBasicShapeValues.h"
+#include "core/css/CSSColorValue.h"
 #include "core/css/CSSContentDistributionValue.h"
 #include "core/css/CSSCustomIdentValue.h"
 #include "core/css/CSSFontFamilyValue.h"
@@ -156,6 +157,11 @@ FilterOperations StyleBuilderConverter::convertFilterOperations(
   return FilterOperationResolver::createFilterOperations(state, value);
 }
 
+FilterOperations StyleBuilderConverter::convertOffscreenFilterOperations(
+    const CSSValue& value) {
+  return FilterOperationResolver::createOffscreenFilterOperations(value);
+}
+
 static FontDescription::GenericFamilyType convertGenericFamily(
     CSSValueID valueID) {
   switch (valueID) {
@@ -328,6 +334,36 @@ float StyleBuilderConverter::convertFontSizeAdjust(StyleResolverState& state,
   return primitiveValue.getFloatValue();
 }
 
+double StyleBuilderConverter::convertValueToNumber(
+    const CSSFunctionValue* filter,
+    const CSSPrimitiveValue* value) {
+  switch (filter->functionType()) {
+    case CSSValueGrayscale:
+    case CSSValueSepia:
+    case CSSValueSaturate:
+    case CSSValueInvert:
+    case CSSValueBrightness:
+    case CSSValueContrast:
+    case CSSValueOpacity: {
+      double amount = (filter->functionType() == CSSValueBrightness) ? 0 : 1;
+      if (filter->length() == 1) {
+        amount = value->getDoubleValue();
+        if (value->isPercentage())
+          amount /= 100;
+      }
+      return amount;
+    }
+    case CSSValueHueRotate: {
+      double angle = 0;
+      if (filter->length() == 1)
+        angle = value->computeDegrees();
+      return angle;
+    }
+    default:
+      return 0;
+  }
+}
+
 FontWeight StyleBuilderConverter::convertFontWeight(StyleResolverState& state,
                                                     const CSSValue& value) {
   const CSSIdentifierValue& identifierValue = toCSSIdentifierValue(value);
@@ -1000,25 +1036,48 @@ LengthSize StyleBuilderConverter::convertRadius(StyleResolverState& state,
   return LengthSize(radiusWidth, radiusHeight);
 }
 
-ShadowData StyleBuilderConverter::convertShadow(StyleResolverState& state,
-                                                const CSSValue& value) {
+ShadowData StyleBuilderConverter::convertShadow(
+    const CSSToLengthConversionData& conversionData,
+    StyleResolverState* state,
+    const CSSValue& value) {
   const CSSShadowValue& shadow = toCSSShadowValue(value);
-  float x = shadow.x->computeLength<float>(state.cssToLengthConversionData());
-  float y = shadow.y->computeLength<float>(state.cssToLengthConversionData());
+  float x = shadow.x->computeLength<float>(conversionData);
+  float y = shadow.y->computeLength<float>(conversionData);
   float blur =
-      shadow.blur
-          ? shadow.blur->computeLength<float>(state.cssToLengthConversionData())
-          : 0;
-  float spread = shadow.spread
-                     ? shadow.spread->computeLength<float>(
-                           state.cssToLengthConversionData())
-                     : 0;
+      shadow.blur ? shadow.blur->computeLength<float>(conversionData) : 0;
+  float spread =
+      shadow.spread ? shadow.spread->computeLength<float>(conversionData) : 0;
   ShadowStyle shadowStyle =
       shadow.style && shadow.style->getValueID() == CSSValueInset ? Inset
                                                                   : Normal;
   StyleColor color = StyleColor::currentColor();
-  if (shadow.color)
-    color = convertStyleColor(state, *shadow.color);
+  if (shadow.color) {
+    if (state) {
+      color = convertStyleColor(*state, *shadow.color);
+    } else {
+      // For OffScreen canvas, we default to black and only parse non
+      // Document dependent CSS colors.
+      color = StyleColor(Color::black);
+      if (shadow.color->isColorValue()) {
+        color = toCSSColorValue(*shadow.color).value();
+      } else {
+        CSSValueID valueID = toCSSIdentifierValue(*shadow.color).getValueID();
+        switch (valueID) {
+          case CSSValueInvalid:
+            NOTREACHED();
+          case CSSValueInternalQuirkInherit:
+          case CSSValueWebkitLink:
+          case CSSValueWebkitActivelink:
+          case CSSValueWebkitFocusRingColor:
+          case CSSValueCurrentcolor:
+            break;
+          default:
+            color = StyleColor::colorFromKeyword(valueID);
+        }
+      }
+    }
+  }
+
   return ShadowData(FloatPoint(x, y), blur, spread, shadowStyle, color);
 }
 
@@ -1031,8 +1090,10 @@ PassRefPtr<ShadowList> StyleBuilderConverter::convertShadowList(
   }
 
   ShadowDataVector shadows;
-  for (const auto& item : toCSSValueList(value))
-    shadows.push_back(convertShadow(state, *item));
+  for (const auto& item : toCSSValueList(value)) {
+    shadows.push_back(
+        convertShadow(state.cssToLengthConversionData(), &state, *item));
+  }
 
   return ShadowList::adopt(shadows);
 }