Based on upstream commit - https://github.com/servo/servo/commit/98e4a53b7241d562d127e0f7005ffb38f21d1380.patch

---
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -235,7 +235,7 @@
 version = "0.49.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cexpr 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "clang-sys 0.28.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -497,7 +497,7 @@
 dependencies = [
  "ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "term_size 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "textwrap 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -510,7 +510,7 @@
 version = "0.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -563,7 +563,7 @@
 version = "0.17.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-foundation 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "foreign-types 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -801,7 +801,7 @@
 version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cubeb-sys 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1140,7 +1140,7 @@
 version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1630,7 +1630,7 @@
 version = "0.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
  "lmdb-rkv-sys 0.8.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -2004,7 +2004,7 @@
 name = "nsstring"
 version = "0.1.0"
 dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "encoding_rs 0.8.16 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2228,7 +2228,7 @@
 version = "0.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "deflate 0.7.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "inflate 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-iter 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2283,7 +2283,7 @@
 name = "pulse"
 version = "0.2.0"
 dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "pulse-ffi 0.1.0",
 ]
 
@@ -2665,7 +2665,7 @@
 name = "selectors"
 version = "0.21.0"
 dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "derive_more 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "fxhash 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2881,7 +2881,7 @@
  "arrayvec 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "atomic_refcell 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bindgen 0.49.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "derive_more 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2944,7 +2944,7 @@
 version = "0.0.1"
 dependencies = [
  "app_units 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.19.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3328,7 +3328,7 @@
 name = "u2fhid"
 version = "0.2.3"
 dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "boxfnonce 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-foundation 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "devd-rs 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3493,7 +3493,7 @@
 dependencies = [
  "base64 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bincode 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-foundation 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3533,7 +3533,7 @@
 dependencies = [
  "app_units 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bincode 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-foundation 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-graphics 0.17.1 (registry+https://github.com/rust-lang/crates.io-index)",
--- a/servo/components/style/stylesheets/viewport_rule.rs
+++ b/servo/components/style/stylesheets/viewport_rule.rs
@@ -291,15 +291,18 @@ impl<'a, 'b, 'i> DeclarationParser<'i> for ViewportRuleParser<'a, 'b> {
     ) -> Result<Vec<ViewportDescriptorDeclaration>, ParseError<'i>> {
         macro_rules! declaration {
             ($declaration:ident($parse:expr)) => {
-                declaration!($declaration(value: try!($parse(input)),
-                                          important: input.try(parse_important).is_ok()))
+                declaration!($declaration {
+                    value: $parse(input)?,
+                    important: input.try(parse_important).is_ok(),
+                })
             };
-            ($declaration:ident(value: $value:expr, important: $important:expr)) => {
+            ($declaration:ident { value: $value:expr, important: $important:expr, }) => {
                 ViewportDescriptorDeclaration::new(
                     self.context.stylesheet_origin,
                     ViewportDescriptor::$declaration($value),
-                    $important)
-            }
+                    $important,
+                )
+            };
         }
 
         macro_rules! ok {
@@ -311,8 +314,14 @@ impl<'a, 'b, 'i> DeclarationParser<'i> for ViewportRuleParser<'a, 'b> {
                 let important = input.try(parse_important).is_ok();
 
                 Ok(vec![
-                    declaration!($min(value: shorthand.0, important: important)),
-                    declaration!($max(value: shorthand.1, important: important)),
+                    declaration!($min {
+                        value: shorthand.0,
+                        important: important,
+                    }),
+                    declaration!($max {
+                        value: shorthand.1,
+                        important: important,
+                    }),
                 ])
             }};
         }