Add support for converting cc::FilterOperations into an SkImageFilter

cc/output/filter_operation.cc

Index: cc/output/filter_operation.cc
diff --git a/cc/output/filter_operation.cc b/cc/output/filter_operation.cc
index de59cfc1c0d4102290177bfa820f588c970eaad2..27106fac0c679ef84f83be61fc6c9f28058ba2da 100644
--- a/cc/output/filter_operation.cc
+++ b/cc/output/filter_operation.cc
@@ -20,6 +20,8 @@ bool FilterOperation::operator==(const FilterOperation& other) const {
            drop_shadow_offset_ == other.drop_shadow_offset_ &&
            drop_shadow_color_ == other.drop_shadow_color_;
   }
+  if (type_ == REFERENCE)
+    return image_filter_.get() == other.image_filter_.get();
   return amount_ == other.amount_;
 }
 
@@ -31,6 +33,7 @@ FilterOperation::FilterOperation(FilterType type, float amount)
       zoom_inset_(0) {
   DCHECK_NE(type_, DROP_SHADOW);
   DCHECK_NE(type_, COLOR_MATRIX);
+  DCHECK_NE(type_, REFERENCE);
   memset(matrix_, 0, sizeof(matrix_));
 }
 
@@ -67,6 +70,33 @@ FilterOperation::FilterOperation(FilterType type, float amount, int inset)
   memset(matrix_, 0, sizeof(matrix_));
 }
 
+FilterOperation::FilterOperation(
+    FilterType type,
+    const skia::RefPtr<SkImageFilter>& image_filter)
+    : type_(type),
+      amount_(0),
+      drop_shadow_offset_(0, 0),
+      drop_shadow_color_(0),
+      image_filter_(image_filter),
+      zoom_inset_(0) {
+  DCHECK_EQ(type_, REFERENCE);
+  DCHECK(image_filter.get());
+  memset(matrix_, 0, sizeof(matrix_));
+}
+
+FilterOperation::FilterOperation(const FilterOperation& other)
+    : type_(other.type_),
+      amount_(other.amount_),
+      drop_shadow_offset_(other.drop_shadow_offset_),
+      drop_shadow_color_(other.drop_shadow_color_),
+      image_filter_(other.image_filter_),
+      zoom_inset_(other.zoom_inset_) {
+  memcpy(matrix_, other.matrix_, sizeof(matrix_));
+}
+
+FilterOperation::~FilterOperation() {
+}
+
 // TODO(ajuma): Define a version of ui::Tween::ValueBetween for floats, and use
 // that instead.
 static float BlendFloats(float from, float to, double progress) {
@@ -146,6 +176,7 @@ static FilterOperation CreateNoOpFilter(FilterOperation::FilterType type) {
       return FilterOperation::CreateZoomFilter(1.f, 0);
     case FilterOperation::SATURATING_BRIGHTNESS:
       return FilterOperation::CreateSaturatingBrightnessFilter(0.f);
+    case FilterOperation::REFERENCE:
     default:
       NOTREACHED();
       return FilterOperation::CreateEmptyFilter();
@@ -172,6 +203,7 @@ static float ClampAmountForFilterType(float amount,
     case FilterOperation::SATURATING_BRIGHTNESS:
       return amount;
     case FilterOperation::COLOR_MATRIX:
+    case FilterOperation::REFERENCE:
     default:
       NOTREACHED();
       return amount;
@@ -187,6 +219,14 @@ FilterOperation FilterOperation::Blend(const FilterOperation* from,
   if (!from && !to)
     return blended_filter;
 
+  if ((from && from->type() == FilterOperation::REFERENCE) ||
+      (to && to->type() == FilterOperation::REFERENCE)) {
+    if (progress > 0.5)

[Stephen White, 2013/07/31 19:18:51]

Heh.. I guess it's better than nothing!  :)

+      return to ? *to : blended_filter;
+    else
+      return from ? *from : blended_filter;
+  }
+
   const FilterOperation& from_op = from ? *from : CreateNoOpFilter(to->type());
   const FilterOperation& to_op = to ? *to : CreateNoOpFilter(from->type());