Adds filter support for offscreen canvas

third_party/WebKit/Source/core/css/resolver/FilterOperationResolver.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, 2013 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 110 matching lines @@
     FilterOperations operations;
 
     if (inValue.isPrimitiveValue()) {
         ASSERT(toCSSPrimitiveValue(inValue).getValueID() == CSSValueNone);
         return operations;
     }
 
     const CSSToLengthConversionData& conversionData = state.cssToLengthConversionData();
     for (auto& currValue : toCSSValueList(inValue)) {
         if (currValue->isURIValue()) {
-            countFilterUse(FilterOperation::REFERENCE, state.document());
+            if (state.hasDocument())
+                countFilterUse(FilterOperation::REFERENCE, state.document());
 
             const CSSURIValue& urlValue = toCSSURIValue(*currValue);
             SVGURLReferenceResolver resolver(urlValue.value(), state.document());
             ReferenceFilterOperation* operation = ReferenceFilterOperation::create(urlValue.value(), resolver.fragmentIdentifier());
             if (!resolver.isLocal()) {
                 if (!urlValue.loadRequested())
                     state.elementStyleResources().addPendingSVGDocument(operation, &urlValue);
                 else if (urlValue.cachedDocument())
                     ReferenceFilterBuilder::setDocumentResourceReference(operation, new DocumentResourceReference(urlValue.cachedDocument()));
             }
             operations.operations().append(operation);
             continue;
         }
 
         const CSSFunctionValue* filterValue = toCSSFunctionValue(currValue.get());
         FilterOperation::OperationType operationType = filterOperationForType(filterValue->functionType());
-        countFilterUse(operationType, state.document());
+        if (state.hasDocument())
+            countFilterUse(operationType, state.document());
         DCHECK_LE(filterValue->length(), 1u);
 
         const CSSPrimitiveValue* firstValue = filterValue->length() && filterValue->item(0).isPrimitiveValue() ? &toCSSPrimitiveValue(filterValue->item(0)) : nullptr;
         switch (filterValue->functionType()) {
         case CSSValueGrayscale:
         case CSSValueSepia:
         case CSSValueSaturate: {
             double amount = 1;
             if (filterValue->length() == 1) {
                 amount = firstValue->getDoubleValue();
@@ skipping 47 matching lines @@
         default:
             ASSERT_NOT_REACHED();
             break;
         }
     }
 
     return operations;
 }
 
 } // namespace blink