Add svg mods and move SVG-related types into them.

components/style/values/computed/svg.rs

@@ -0,0 +1,33 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! Computed types for SVG properties.
+
+use values::RGBA;
+use values::generics::svg as generic;
+
+/// Computed SVG Paint value
+pub type SVGPaint = generic::SVGPaint<RGBA>;
+/// Computed SVG Paint Kind value
+pub type SVGPaintKind = generic::SVGPaintKind<RGBA>;
+
+impl Default for SVGPaint {
+    fn default() -> Self {
+        SVGPaint {
+            kind: generic::SVGPaintKind::None,
+            fallback: None,
+        }
+    }
+}
+
+impl SVGPaint {
+    /// Opaque black color
+    pub fn black() -> Self {
+        let rgba = RGBA::from_floats(0., 0., 0., 1.);
+        SVGPaint {
+            kind: generic::SVGPaintKind::Color(rgba),
+            fallback: None,
+        }
+    }
+}