Add support for converting cc::FilterOperations into an SkImageFilter

cc/output/filter_operations.cc

Index: cc/output/filter_operations.cc
diff --git a/cc/output/filter_operations.cc b/cc/output/filter_operations.cc
index e526f5c419bed3ae53cbab223109f19c85ec385b..08bac31d8df9f111c3e120db8a3fc229ac41c9c1 100644
--- a/cc/output/filter_operations.cc
+++ b/cc/output/filter_operations.cc
@@ -85,6 +85,7 @@ bool FilterOperations::HasFilterThatMovesPixels() const {
       case FilterOperation::BLUR:
       case FilterOperation::DROP_SHADOW:
       case FilterOperation::ZOOM:
+      case FilterOperation::REFERENCE:

[danakj, 2013/09/09 22:04:50]

Should we DCHECK() that this is not called with REFERENCE since the outsets will
be invalid?

[ajuma, 2013/09/10 21:17:58]

Done. Also added a DCHECK to GetOutsets for the same reason.

         return true;
       case FilterOperation::OPACITY:
       case FilterOperation::COLOR_MATRIX:
@@ -110,6 +111,7 @@ bool FilterOperations::HasFilterThatAffectsOpacity() const {
       case FilterOperation::BLUR:
       case FilterOperation::DROP_SHADOW:
       case FilterOperation::ZOOM:
+      case FilterOperation::REFERENCE:
         return true;
       case FilterOperation::COLOR_MATRIX: {
         const SkScalar* matrix = op.matrix();
@@ -135,6 +137,14 @@ bool FilterOperations::HasFilterThatAffectsOpacity() const {
   return false;
 }
 
+bool FilterOperations::HasReferenceFilter() const {
+  for (size_t i = 0; i < operations_.size(); ++i) {
+    if (operations_[i].type() == FilterOperation::REFERENCE)
+      return true;
+  }
+  return false;
+}
+
 FilterOperations FilterOperations::Blend(const FilterOperations& from,
                                          double progress) const {
   FilterOperations blended_filters;