Implement cc::FilterOperation StructTraits

cc/ipc/filter_operation.mojom

Index: cc/ipc/filter_operation.mojom
diff --git a/cc/ipc/filter_operation.mojom b/cc/ipc/filter_operation.mojom
new file mode 100644
index 0000000000000000000000000000000000000000..6bcb0733cc1b7887241537b1edfd88dc97d526d3
--- /dev/null
+++ b/cc/ipc/filter_operation.mojom
@@ -0,0 +1,40 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+module cc.mojom;
+
+import "skia/public/interfaces/image_filter.mojom";
+import "ui/gfx/geometry/mojo/geometry.mojom";
+
+enum FilterType {
+  GRAYSCALE,
+  SEPIA,
+  SATURATE,
+  HUE_ROTATE,
+  INVERT,
+  BRIGHTNESS,
+  CONTRAST,
+  OPACITY,
+  BLUR,
+  DROP_SHADOW,
+  COLOR_MATRIX,
+  ZOOM,
+  REFERENCE,
+  SATURATING_BRIGHTNESS,  // Not used in CSS/SVG.

[enne (OOO), 2016/06/08 18:06:52]

I'm not sure it's worth perpetuating this comment.

[Fady Samuel, 2016/06/08 19:23:20]

Done.

+  ALPHA_THRESHOLD,  // Not used in CSS/SVG.
+  FILTER_TYPE_LAST = ALPHA_THRESHOLD
+};
+
+// See cc/output/filter_operation.h.
+struct FilterOperation {
+  FilterType type;
+  float amount;
+  gfx.mojom.Point? drop_shadow_offset;
+  uint32 drop_shadow_color;
+  skia.mojom.ImageFilter? image_filter;
+  array<float, 20>? matrix;
+  int32 zoom_inset;
+  // Note: SkRegion is currently not needed for serialization.
+};
+