blink: Add backdrop-filter support

Source/core/paint/DeprecatedPaintLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 205 matching lines @@
 bool DeprecatedPaintLayer::paintsWithFilters() const
 {
     if (!layoutObject()->hasFilter())
         return false;
 
     // https://code.google.com/p/chromium/issues/detail?id=343759
     DisableCompositingQueryAsserts disabler;
     return !m_compositedDeprecatedPaintLayerMapping || compositingState() != PaintsIntoOwnBacking;
 }
 
+bool DeprecatedPaintLayer::paintsWithBackdropFilters() const
+{
+    if (!layoutObject()->hasBackdropFilter())
+        return false;
+
+    // https://code.google.com/p/chromium/issues/detail?id=343759
+    DisableCompositingQueryAsserts disabler;
+    return !m_compositedDeprecatedPaintLayerMapping || compositingState() != PaintsIntoOwnBacking;
+}
+
 LayoutSize DeprecatedPaintLayer::subpixelAccumulation() const
 {
     return m_subpixelAccumulation;
 }
 
 void DeprecatedPaintLayer::setSubpixelAccumulation(const LayoutSize& size)
 {
     m_subpixelAccumulation = size;
 }
 
@@ skipping 2298 matching lines @@
 }
 
 bool DeprecatedPaintLayer::scrollsOverflow() const
 {
     if (DeprecatedPaintLayerScrollableArea* scrollableArea = this->scrollableArea())
         return scrollableArea->scrollsOverflow();
 
     return false;
 }
 
-FilterOperations DeprecatedPaintLayer::computeFilterOperations(const ComputedStyle& style)
+namespace {
+
+FilterOperations computeFilterOperationsHandleReferenceFilters(const FilterOperations& filters, float effectiveZoom, Node* enclosingElement)
 {
-    const FilterOperations& filters = style.filter();
     if (filters.hasReferenceFilter()) {
         for (size_t i = 0; i < filters.size(); ++i) {
             FilterOperation* filterOperation = filters.operations().at(i).get();
             if (filterOperation->type() != FilterOperation::REFERENCE)
                 continue;
             ReferenceFilterOperation& referenceOperation = toReferenceFilterOperation(*filterOperation);
             // FIXME: Cache the ReferenceFilter if it didn't change.
-            RefPtrWillBeRawPtr<ReferenceFilter> referenceFilter = ReferenceFilterBuilder::build(style.effectiveZoom(), toElement(enclosingElement()), nullptr, referenceOperation);
+            RefPtrWillBeRawPtr<ReferenceFilter> referenceFilter = ReferenceFilterBuilder::build(effectiveZoom, toElement(enclosingElement), nullptr, referenceOperation);
             referenceOperation.setFilter(referenceFilter.release());
         }
     }
 
     return filters;
 }
 
+} // unnamed namespace
+
+FilterOperations DeprecatedPaintLayer::computeFilterOperations(const ComputedStyle& style)
+{
+    return computeFilterOperationsHandleReferenceFilters(style.filter(), style.effectiveZoom(), enclosingElement());
+}
+
+FilterOperations DeprecatedPaintLayer::computeBackdropFilterOperations(const ComputedStyle& style)
+{
+    return computeFilterOperationsHandleReferenceFilters(style.backdropFilter(), style.effectiveZoom(), enclosingElement());
+}
+
 void DeprecatedPaintLayer::updateOrRemoveFilterClients()
 {
     if (!hasFilter()) {
         removeFilterInfoIfNeeded();
         return;
     }
 
     if (layoutObject()->style()->filter().hasReferenceFilter())
         ensureFilterInfo()->updateReferenceFilterClients(layoutObject()->style()->filter());
     else if (hasFilterInfo())
@@ skipping 99 matching lines @@
 
 void showLayerTree(const blink::LayoutObject* layoutObject)
 {
     if (!layoutObject) {
         fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
         return;
     }
     showLayerTree(layoutObject->enclosingLayer());
 }
 #endif