Add the basic CSSStyleDeclaration CSSOM interface.

This just includes the .webidl file (with some of the functionality
commented out) and the stub implementations for the bindings.

This is another step towards #1721.

components/script/dom/cssstyledeclaration.rs

@@ -0,0 +1,68 @@
+/* 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/. */
+
+use dom::bindings::codegen::Bindings::CSSStyleDeclarationBinding::CSSStyleDeclarationMethods;
+use dom::bindings::error::{ErrorResult, Fallible};
+use dom::bindings::utils::{Reflectable, Reflector};
+use dom::bindings::js::JSRef;
+use servo_util::str::DOMString;
+
+#[dom_struct]
+pub struct CSSStyleDeclaration {
+    reflector_: Reflector,
+}
+
+impl<'a> CSSStyleDeclarationMethods for JSRef<'a, CSSStyleDeclaration> {
+    fn CssText(self) -> DOMString {
+        "".to_string()
+    }
+
+    fn SetCssText(self, _cssText: DOMString) -> ErrorResult {
+        Ok(())
+    }
+
+    fn Length(self) -> u32 {
+        0
+    }
+
+    fn Item(self, _index: u32) -> DOMString {
+        "".to_string()
+    }
+
+    fn GetPropertyValue(self, _property: DOMString) -> DOMString {
+        "".to_string()
+    }
+
+    fn GetPropertyPriority(self, _property: DOMString) -> DOMString {
+        "".to_string()
+    }
+
+    fn SetProperty(self, _property: DOMString, _value: DOMString,
+                   _priority: DOMString) -> ErrorResult {
+        Ok(())
+    }
+
+    fn SetPropertyValue(self, _property: DOMString, _value: DOMString) -> ErrorResult {
+        Ok(())
+    }
+
+    fn SetPropertyPriority(self, _property: DOMString, _priority: DOMString) -> ErrorResult {
+        Ok(())
+    }
+
+    fn RemoveProperty(self, _property: DOMString) -> Fallible<DOMString> {
+        Ok("".to_string())
+    }
+
+    fn IndexedGetter(self, _index: u32, _found: &mut bool) -> DOMString {
+        "".to_string()
+    }
+}
+
+impl Reflectable for CSSStyleDeclaration {
+    fn reflector<'a>(&'a self) -> &'a Reflector {
+        &self.reflector_
+    }
+}
+