style: Drop frames() timing function.

frames() timing function was removed from the spec, so we drop it.
Besides, some devtool tests are removed because they use frame(). I will
add them back by using new step function later.

Differential Revision: https://phabricator.services.mozilla.com/D9309

components/style/animation.rs

@@ -369,22 +369,6 @@ impl PropertyAnimation {
             GenericTimingFunction::Steps(steps, StepPosition::End) => {
                 (time * (steps as f64)).floor() / (steps as f64)
             },
-            GenericTimingFunction::Frames(frames) => {
-                // https://drafts.csswg.org/css-timing/#frames-timing-functions
-                let mut out = (time * (frames as f64)).floor() / ((frames - 1) as f64);
-                if out > 1.0 {
-                    // FIXME: Basically, during the animation sampling process, the input progress
-                    // should be in the range of [0, 1]. However, |time| is not accurate enough
-                    // here, which means |time| could be larger than 1.0 in the last animation
-                    // frame. (It should be equal to 1.0 exactly.) This makes the output of frames
-                    // timing function jumps to the next frame/level.
-                    // However, this solution is still not correct because |time| is possible
-                    // outside the range of [0, 1] after introducing Web Animations. We should fix
-                    // this problem when implementing web animations.
-                    out = 1.0;
-                }
-                out
-            },
             GenericTimingFunction::Keyword(keyword) => {
                 let (x1, x2, y1, y2) = keyword.to_bezier();
                 Bezier::new(x1, x2, y1, y2).solve(time, epsilon)

components/style/gecko_bindings/sugar/ns_timing_function.rs

@@ -22,17 +22,7 @@ impl nsTimingFunction {
             self.__bindgen_anon_1
                 .__bindgen_anon_1
                 .as_mut()
-                .mStepsOrFrames = steps;
-        }
-    }
-
-    fn set_as_frames(&mut self, frames: u32) {
-        self.mType = nsTimingFunction_Type::Frames;
-        unsafe {
-            self.__bindgen_anon_1
-                .__bindgen_anon_1
-                .as_mut()
-                .mStepsOrFrames = frames;
+                .mSteps = steps;
         }
     }
 
@@ -74,10 +64,6 @@ impl From<TimingFunction> for nsTimingFunction {
                 debug_assert!(steps.value() >= 0);
                 tf.set_as_step(nsTimingFunction_Type::StepEnd, steps.value() as u32);
             },
-            GenericTimingFunction::Frames(frames) => {
-                debug_assert!(frames.value() >= 2);
-                tf.set_as_frames(frames.value() as u32);
-            },
             GenericTimingFunction::CubicBezier { x1, y1, x2, y2 } => {
                 tf.set_as_bezier(
                     nsTimingFunction_Type::CubicBezier,
@@ -105,7 +91,7 @@ impl From<nsTimingFunction> for ComputedTimingFunction {
                         .__bindgen_anon_1
                         .__bindgen_anon_1
                         .as_ref()
-                        .mStepsOrFrames
+                        .mSteps
                 },
                 StepPosition::Start,
             ),
@@ -115,17 +101,10 @@ impl From<nsTimingFunction> for ComputedTimingFunction {
                         .__bindgen_anon_1
                         .__bindgen_anon_1
                         .as_ref()
-                        .mStepsOrFrames
+                        .mSteps
                 },
                 StepPosition::End,
             ),
-            nsTimingFunction_Type::Frames => GenericTimingFunction::Frames(unsafe {
-                function
-                    .__bindgen_anon_1
-                    .__bindgen_anon_1
-                    .as_ref()
-                    .mStepsOrFrames
-            }),
             nsTimingFunction_Type::Ease => GenericTimingFunction::Keyword(TimingKeyword::Ease),
             nsTimingFunction_Type::Linear => GenericTimingFunction::Keyword(TimingKeyword::Linear),
             nsTimingFunction_Type::EaseIn => GenericTimingFunction::Keyword(TimingKeyword::EaseIn),

components/style/values/generics/transform.rs

@@ -92,7 +92,7 @@ pub struct TransformOrigin<H, V, Depth> {
 
 /// A generic timing function.
 ///
-/// <https://drafts.csswg.org/css-timing-1/#single-timing-function-production>
+/// https://drafts.csswg.org/css-easing-1/#timing-functions
 #[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
 #[value_info(ty = "TIMING_FUNCTION")]
 pub enum TimingFunction<Integer, Number> {
@@ -111,9 +111,6 @@ pub enum TimingFunction<Integer, Number> {
     #[css(comma, function)]
     #[value_info(other_values = "step-start,step-end")]
     Steps(Integer, #[css(skip_if = "is_end")] StepPosition),
-    /// `frames(<integer>)`
-    #[css(comma, function)]
-    Frames(Integer),
 }
 
 #[allow(missing_docs)]

components/style/values/specified/transform.rs

@@ -350,19 +350,6 @@ impl<S> OriginComponent<S> {
     }
 }
 
-#[cfg(feature = "gecko")]
-#[inline]
-fn allow_frames_timing() -> bool {
-    use gecko_bindings::structs::mozilla;
-    unsafe { mozilla::StaticPrefs_sVarCache_layout_css_frames_timing_enabled }
-}
-
-#[cfg(feature = "servo")]
-#[inline]
-fn allow_frames_timing() -> bool {
-    true
-}
-
 impl Parse for TimingFunction {
     fn parse<'i, 't>(
         context: &ParserContext,
@@ -406,14 +393,6 @@ impl Parse for TimingFunction {
                     }).unwrap_or(StepPosition::End);
                     Ok(generic::TimingFunction::Steps(steps, position))
                 },
-                "frames" => {
-                    if allow_frames_timing() {
-                        let frames = Integer::parse_with_minimum(context, i, 2)?;
-                        Ok(generic::TimingFunction::Frames(frames))
-                    } else {
-                        Err(())
-                    }
-                },
                 _ => Err(()),
             }).map_err(|()| {
                 location.new_custom_error(StyleParseErrorKind::UnexpectedFunction(function.clone()))
@@ -440,9 +419,6 @@ impl ToComputedValue for TimingFunction {
             generic::TimingFunction::Steps(steps, position) => {
                 generic::TimingFunction::Steps(steps.to_computed_value(context) as u32, position)
             },
-            generic::TimingFunction::Frames(frames) => {
-                generic::TimingFunction::Frames(frames.to_computed_value(context) as u32)
-            },
         }
     }
 
@@ -465,9 +441,6 @@ impl ToComputedValue for TimingFunction {
                 Integer::from_computed_value(&(steps as i32)),
                 position,
             ),
-            generic::TimingFunction::Frames(frames) => {
-                generic::TimingFunction::Frames(Integer::from_computed_value(&(frames as i32)))
-            },
         }
     }
 }