[poc] curve-filter

cc/layers/picture_image_layer.cc

Index: cc/layers/picture_image_layer.cc
diff --git a/cc/layers/picture_image_layer.cc b/cc/layers/picture_image_layer.cc
index b5a55c237d081c1e488464418b2ed1b6eeb41cd3..4121d894bd3d5bb4759ddf4812b4375a95f18b54 100644
--- a/cc/layers/picture_image_layer.cc
+++ b/cc/layers/picture_image_layer.cc
@@ -10,8 +10,10 @@
 #include "cc/playback/display_item_list_settings.h"
 #include "cc/playback/drawing_display_item.h"
 #include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkColorFilter.h"
 #include "third_party/skia/include/core/SkImage.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
+#include "third_party/skia/include/effects/SkColorFilterImageFilter.h"
 #include "ui/gfx/skia_util.h"
 
 namespace cc {
@@ -38,7 +40,23 @@ bool PictureImageLayer::HasDrawableContent() const {
   return image_ && PictureLayer::HasDrawableContent();
 }
 
-void PictureImageLayer::SetImage(skia::RefPtr<const SkImage> image) {
+void PictureImageLayer::SetImage(skia::RefPtr<const SkImage> image,
+    skia::RefPtr<SkColorFilter> transform) {
+  // SetImage() may be called when color transforms change: usually
+  // the image has not changed, but its rendered paint should.
+  if (transform_.get() != transform.get()) {
+    transform_ = std::move(transform);
+    FilterOperations filters;
+    if (transform_.get()) {
+      skia::RefPtr<SkImageFilter> color_transform_filter =
+          skia::AdoptRef(SkColorFilterImageFilter::Create(transform_.get()));
+      FilterOperation color_transform_operation =
+          FilterOperation::CreateReferenceFilter(color_transform_filter);
+      filters.Append(color_transform_operation);
+    }
+    this->Layer::SetFilters(filters);
+  }
+
   // SetImage() currently gets called whenever there is any
   // style change that affects the layer even if that change doesn't
   // affect the actual contents of the image (e.g. a CSS animation).