Auto merge of #23477 - est31:unused_code_removal, r=jdm

Remove unused code (1/N)

<!-- Please describe your changes on the following line: -->

First PR in a series of PRs to remove unused/dead code from servo, powered by an (upcoming) tool of mine. Please take a look and tell me if you want to keep something.

---
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #___ (GitHub issue number if applicable)

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- [ ] There are tests for these changes OR
- [x] These changes do not require tests because they only remove dead code

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10 files changed, 2 insertions, 242 deletions

diff --git a/components/gfx/text/glyph.rs b/components/gfx/text/glyph.rs
index d84570442ab..df8180688f0 100644
--- a/components/gfx/text/glyph.rs
+++ b/components/gfx/text/glyph.rs
@@ -105,8 +105,6 @@ fn is_simple_advance(advance: Au) -> bool {
     }
 }
 
-pub type DetailedGlyphCount = u16;
-
 // Getters and setters for GlyphEntry. Setter methods are functional,
 // because GlyphEntry is immutable and only a u32 in size.
 impl GlyphEntry {
diff --git a/components/gfx/text/text_run.rs b/components/gfx/text/text_run.rs
index 12bee8a8e39..17eb5bf623a 100644
--- a/components/gfx/text/text_run.rs
+++ b/components/gfx/text/text_run.rs
@@ -280,10 +280,6 @@ impl<'a> TextRun {
         self.font_metrics.ascent
     }
 
-    pub fn descent(&self) -> Au {
-        self.font_metrics.descent
-    }
-
     pub fn advance_for_range(&self, range: &Range<ByteIndex>) -> Au {
         if range.is_empty() {
             return Au(0);
diff --git a/components/layout/display_list/items.rs b/components/layout/display_list/items.rs
index c66f0c8942b..10d3b81a8d8 100644
--- a/components/layout/display_list/items.rs
+++ b/components/layout/display_list/items.rs
@@ -27,7 +27,7 @@ use webrender_api as wr;
 use webrender_api::{BorderRadius, ClipMode};
 use webrender_api::{ComplexClipRegion, ExternalScrollId, FilterOp};
 use webrender_api::{GlyphInstance, GradientStop, ImageKey, LayoutPoint};
-use webrender_api::{LayoutRect, LayoutSize, LayoutTransform, LayoutVector2D};
+use webrender_api::{LayoutRect, LayoutSize, LayoutTransform};
 use webrender_api::{MixBlendMode, ScrollSensitivity, Shadow};
 use webrender_api::{StickyOffsetBounds, TransformStyle};
 
@@ -510,62 +510,6 @@ impl ClippingRegion {
         }
     }
 
-    /// Mutates this clipping region to intersect with the given rectangle.
-    ///
-    /// TODO(pcwalton): This could more eagerly eliminate complex clipping regions, at the cost of
-    /// complexity.
-    #[inline]
-    pub fn intersect_rect(&mut self, rect: &LayoutRect) {
-        self.main = self.main.intersection(rect).unwrap_or(LayoutRect::zero())
-    }
-
-    /// Returns true if this clipping region might be nonempty. This can return false positives,
-    /// but never false negatives.
-    #[inline]
-    pub fn might_be_nonempty(&self) -> bool {
-        !self.main.is_empty()
-    }
-
-    /// Returns true if this clipping region might contain the given point and false otherwise.
-    /// This is a quick, not a precise, test; it can yield false positives.
-    #[inline]
-    pub fn might_intersect_point(&self, point: &LayoutPoint) -> bool {
-        self.main.contains(point) &&
-            self.complex
-                .iter()
-                .all(|complex| complex.rect.contains(point))
-    }
-
-    /// Returns true if this clipping region might intersect the given rectangle and false
-    /// otherwise. This is a quick, not a precise, test; it can yield false positives.
-    #[inline]
-    pub fn might_intersect_rect(&self, rect: &LayoutRect) -> bool {
-        self.main.intersects(rect) &&
-            self.complex
-                .iter()
-                .all(|complex| complex.rect.intersects(rect))
-    }
-
-    /// Returns true if this clipping region completely surrounds the given rect.
-    #[inline]
-    pub fn does_not_clip_rect(&self, rect: &LayoutRect) -> bool {
-        self.main.contains(&rect.origin) &&
-            self.main.contains(&rect.bottom_right()) &&
-            self.complex.iter().all(|complex| {
-                complex.rect.contains(&rect.origin) && complex.rect.contains(&rect.bottom_right())
-            })
-    }
-
-    /// Returns a bounding rect that surrounds this entire clipping region.
-    #[inline]
-    pub fn bounding_rect(&self) -> LayoutRect {
-        let mut rect = self.main;
-        for complex in &*self.complex {
-            rect = rect.union(&complex.rect)
-        }
-        rect
-    }
-
     /// Intersects this clipping region with the given rounded rectangle.
     #[inline]
     pub fn intersect_with_rounded_rect(&mut self, rect: LayoutRect, radii: BorderRadius) {
@@ -593,28 +537,6 @@ impl ClippingRegion {
 
         self.complex.push(new_complex_region);
     }
-
-    /// Translates this clipping region by the given vector.
-    #[inline]
-    pub fn translate(&self, delta: &LayoutVector2D) -> ClippingRegion {
-        ClippingRegion {
-            main: self.main.translate(delta),
-            complex: self
-                .complex
-                .iter()
-                .map(|complex| ComplexClipRegion {
-                    rect: complex.rect.translate(delta),
-                    radii: complex.radii,
-                    mode: complex.mode,
-                })
-                .collect(),
-        }
-    }
-
-    #[inline]
-    pub fn is_max(&self) -> bool {
-        self.main == LayoutRect::max_rect() && self.complex.is_empty()
-    }
 }
 
 impl fmt::Debug for ClippingRegion {
@@ -776,10 +698,6 @@ impl DisplayItem {
         }
     }
 
-    pub fn scroll_node_index(&self) -> ClipScrollNodeIndex {
-        self.base().clipping_and_scrolling.scrolling
-    }
-
     pub fn clipping_and_scrolling(&self) -> ClippingAndScrolling {
         self.base().clipping_and_scrolling
     }
@@ -795,14 +713,6 @@ impl DisplayItem {
     pub fn bounds(&self) -> LayoutRect {
         self.base().bounds
     }
-
-    pub fn debug_with_level(&self, level: u32) {
-        let mut indent = String::new();
-        for _ in 0..level {
-            indent.push_str("| ")
-        }
-        println!("{}+ {:?}", indent, self);
-    }
 }
 
 impl fmt::Debug for DisplayItem {
diff --git a/components/layout/flex.rs b/components/layout/flex.rs
index 82dd9533175..e6aa2f7b2c8 100644
--- a/components/layout/flex.rs
+++ b/components/layout/flex.rs
@@ -870,10 +870,6 @@ impl Flow for FlexFlow {
         FlowClass::Flex
     }
 
-    fn as_mut_flex(&mut self) -> &mut FlexFlow {
-        self
-    }
-
     fn as_flex(&self) -> &FlexFlow {
         self
     }
diff --git a/components/layout/flow.rs b/components/layout/flow.rs
index 86bd6b74edf..bcc38252b9b 100644
--- a/components/layout/flow.rs
+++ b/components/layout/flow.rs
@@ -35,11 +35,9 @@ use crate::flow_list::{FlowList, FlowListIterator, MutFlowListIterator};
 use crate::flow_ref::{FlowRef, WeakFlowRef};
 use crate::fragment::{CoordinateSystem, Fragment, FragmentBorderBoxIterator, Overflow};
 use crate::inline::InlineFlow;
-use crate::model::{CollapsibleMargins, IntrinsicISizes, MarginCollapseInfo};
-use crate::multicol::MulticolFlow;
+use crate::model::{CollapsibleMargins, IntrinsicISizes};
 use crate::parallel::FlowParallelInfo;
 use crate::table::TableFlow;
-use crate::table_caption::TableCaptionFlow;
 use crate::table_cell::TableCellFlow;
 use crate::table_colgroup::TableColGroupFlow;
 use crate::table_row::TableRowFlow;
@@ -53,7 +51,6 @@ use num_traits::cast::FromPrimitive;
 use serde::ser::{Serialize, SerializeStruct, Serializer};
 use servo_geometry::{au_rect_to_f32_rect, f32_rect_to_au_rect, MaxRect};
 use std::fmt;
-use std::iter::Zip;
 use std::slice::IterMut;
 use std::sync::atomic::Ordering;
 use std::sync::Arc;
@@ -130,11 +127,6 @@ pub trait Flow: HasBaseFlow + fmt::Debug + Sync + Send + 'static {
         panic!("called as_flex() on a non-flex flow")
     }
 
-    /// If this is a flex flow, returns the underlying object, borrowed mutably. Fails otherwise.
-    fn as_mut_flex(&mut self) -> &mut FlexFlow {
-        panic!("called as_mut_flex() on a non-flex flow")
-    }
-
     /// If this is an inline flow, returns the underlying object. Fails otherwise.
     fn as_inline(&self) -> &InlineFlow {
         panic!("called as_inline() on a non-inline flow")
@@ -146,12 +138,6 @@ pub trait Flow: HasBaseFlow + fmt::Debug + Sync + Send + 'static {
         panic!("called as_mut_inline() on a non-inline flow")
     }
 
-    /// If this is a table wrapper flow, returns the underlying object, borrowed mutably. Fails
-    /// otherwise.
-    fn as_mut_table_wrapper(&mut self) -> &mut TableWrapperFlow {
-        panic!("called as_mut_table_wrapper() on a non-tablewrapper flow")
-    }
-
     /// If this is a table wrapper flow, returns the underlying object. Fails otherwise.
     fn as_table_wrapper(&self) -> &TableWrapperFlow {
         panic!("called as_table_wrapper() on a non-tablewrapper flow")
@@ -203,22 +189,10 @@ pub trait Flow: HasBaseFlow + fmt::Debug + Sync + Send + 'static {
 
     /// If this is a table cell flow, returns the underlying object, borrowed mutably. Fails
     /// otherwise.
-    fn as_mut_table_caption(&mut self) -> &mut TableCaptionFlow {
-        panic!("called as_mut_table_caption() on a non-tablecaption flow")
-    }
-
-    /// If this is a table cell flow, returns the underlying object, borrowed mutably. Fails
-    /// otherwise.
     fn as_mut_table_cell(&mut self) -> &mut TableCellFlow {
         panic!("called as_mut_table_cell() on a non-tablecell flow")
     }
 
-    /// If this is a multicol flow, returns the underlying object, borrowed mutably. Fails
-    /// otherwise.
-    fn as_mut_multicol(&mut self) -> &mut MulticolFlow {
-        panic!("called as_mut_multicol() on a non-multicol flow")
-    }
-
     /// If this is a table cell flow, returns the underlying object. Fails otherwise.
     fn as_table_cell(&self) -> &TableCellFlow {
         panic!("called as_table_cell() on a non-tablecell flow")
@@ -432,14 +406,6 @@ pub trait Flow: HasBaseFlow + fmt::Debug + Sync + Send + 'static {
     /// Mutably iterates through fragments in this flow.
     fn mutate_fragments(&mut self, mutator: &mut dyn FnMut(&mut Fragment));
 
-    fn compute_collapsible_block_start_margin(
-        &mut self,
-        _layout_context: &mut LayoutContext,
-        _margin_collapse_info: &mut MarginCollapseInfo,
-    ) {
-        // The default implementation is a no-op.
-    }
-
     /// Marks this flow as the root flow. The default implementation is a no-op.
     fn mark_as_root(&mut self) {
         debug!("called mark_as_root() on a flow of type {:?}", self.class());
@@ -530,9 +496,6 @@ pub trait ImmutableFlowUtils {
     /// Returns true if this flow is a table caption flow.
     fn is_table_caption(self) -> bool;
 
-    /// Returns true if this flow is a proper table child.
-    fn is_proper_table_child(self) -> bool;
-
     /// Returns true if this flow is a table row flow.
     fn is_table_row(self) -> bool;
 
@@ -545,18 +508,9 @@ pub trait ImmutableFlowUtils {
     /// Returns true if this flow is a table rowgroup flow.
     fn is_table_rowgroup(self) -> bool;
 
-    /// Returns true if this flow is one of table-related flows.
-    fn is_table_kind(self) -> bool;
-
-    /// Returns true if this flow has no children.
-    fn is_leaf(self) -> bool;
-
     /// Returns the number of children that this flow possesses.
     fn child_count(self) -> usize;
 
-    /// Return true if this flow is a Block Container.
-    fn is_block_container(self) -> bool;
-
     /// Returns true if this flow is a block flow.
     fn is_block_flow(self) -> bool;
 
@@ -826,8 +780,6 @@ impl<'a> Iterator for AbsoluteDescendantIter<'a> {
     }
 }
 
-pub type AbsoluteDescendantOffsetIter<'a> = Zip<AbsoluteDescendantIter<'a>, IterMut<'a, Au>>;
-
 /// Information needed to compute absolute (i.e. viewport-relative) flow positions (not to be
 /// confused with absolutely-positioned flows) that is computed during block-size assignment.
 #[derive(Clone, Copy)]
@@ -1205,10 +1157,6 @@ impl BaseFlow {
         p as usize
     }
 
-    pub fn flow_id(&self) -> usize {
-        return self as *const BaseFlow as usize;
-    }
-
     pub fn collect_stacking_contexts_for_children(
         &mut self,
         state: &mut StackingContextCollectionState,
@@ -1252,19 +1200,6 @@ impl<'a> ImmutableFlowUtils for &'a dyn Flow {
         self.class().is_block_like()
     }
 
-    /// Returns true if this flow is a proper table child.
-    /// 'Proper table child' is defined as table-row flow, table-rowgroup flow,
-    /// table-column-group flow, or table-caption flow.
-    fn is_proper_table_child(self) -> bool {
-        match self.class() {
-            FlowClass::TableRow |
-            FlowClass::TableRowGroup |
-            FlowClass::TableColGroup |
-            FlowClass::TableCaption => true,
-            _ => false,
-        }
-    }
-
     /// Returns true if this flow is a table row flow.
     fn is_table_row(self) -> bool {
         match self.class() {
@@ -1313,47 +1248,11 @@ impl<'a> ImmutableFlowUtils for &'a dyn Flow {
         }
     }
 
-    /// Returns true if this flow is one of table-related flows.
-    fn is_table_kind(self) -> bool {
-        match self.class() {
-            FlowClass::TableWrapper |
-            FlowClass::Table |
-            FlowClass::TableColGroup |
-            FlowClass::TableRowGroup |
-            FlowClass::TableRow |
-            FlowClass::TableCaption |
-            FlowClass::TableCell => true,
-            _ => false,
-        }
-    }
-
-    /// Returns true if this flow has no children.
-    fn is_leaf(self) -> bool {
-        self.base().children.is_empty()
-    }
-
     /// Returns the number of children that this flow possesses.
     fn child_count(self) -> usize {
         self.base().children.len()
     }
 
-    /// Return true if this flow is a Block Container.
-    ///
-    /// Except for table fragments and replaced elements, block-level fragments (`BlockFlow`) are
-    /// also block container fragments.
-    /// Non-replaced inline blocks and non-replaced table cells are also block
-    /// containers.
-    fn is_block_container(self) -> bool {
-        match self.class() {
-            // TODO: Change this when inline-blocks are supported.
-            FlowClass::Block | FlowClass::TableCaption | FlowClass::TableCell => {
-                // FIXME: Actually check the type of the node
-                self.child_count() != 0
-            },
-            _ => false,
-        }
-    }
-
     /// Returns true if this flow is a block flow.
     fn is_block_flow(self) -> bool {
         match self.class() {
diff --git a/components/layout/flow_list.rs b/components/layout/flow_list.rs
index 0283c15ae81..a27db03920a 100644
--- a/components/layout/flow_list.rs
+++ b/components/layout/flow_list.rs
@@ -73,17 +73,6 @@ impl FlowList {
         self.flows.push_back(FlowRef::new(new_head));
     }
 
-    pub fn back(&self) -> Option<&dyn Flow> {
-        self.flows.back().map(|x| &**x)
-    }
-
-    /// Add an element first in the list
-    ///
-    /// O(1)
-    pub fn push_front(&mut self, new_head: FlowRef) {
-        self.flows.push_front(new_head);
-    }
-
     pub fn push_front_arc(&mut self, new_head: Arc<dyn Flow>) {
         self.flows.push_front(FlowRef::new(new_head));
     }
@@ -92,10 +81,6 @@ impl FlowList {
         self.flows.pop_front().map(FlowRef::into_arc)
     }
 
-    pub fn front(&self) -> Option<&dyn Flow> {
-        self.flows.front().map(|x| &**x)
-    }
-
     /// Create an empty list
     #[inline]
     pub fn new() -> FlowList {
@@ -142,12 +127,6 @@ impl FlowList {
 
     /// O(1)
     #[inline]
-    pub fn is_empty(&self) -> bool {
-        self.flows.is_empty()
-    }
-
-    /// O(1)
-    #[inline]
     pub fn len(&self) -> usize {
         self.flows.len()
     }
diff --git a/components/layout/multicol.rs b/components/layout/multicol.rs
index 46ccbc64653..d49e5f1d79f 100644
--- a/components/layout/multicol.rs
+++ b/components/layout/multicol.rs
@@ -74,10 +74,6 @@ impl Flow for MulticolFlow {
         &self.block_flow
     }
 
-    fn as_mut_multicol(&mut self) -> &mut MulticolFlow {
-        self
-    }
-
     fn bubble_inline_sizes(&mut self) {
         // FIXME(SimonSapin) http://dev.w3.org/csswg/css-sizing/#multicol-intrinsic
         self.block_flow.bubble_inline_sizes();
diff --git a/components/layout/table_caption.rs b/components/layout/table_caption.rs
index 883d5d6501d..3d44190f986 100644
--- a/components/layout/table_caption.rs
+++ b/components/layout/table_caption.rs
@@ -40,10 +40,6 @@ impl Flow for TableCaptionFlow {
         FlowClass::TableCaption
     }
 
-    fn as_mut_table_caption(&mut self) -> &mut TableCaptionFlow {
-        self
-    }
-
     fn as_mut_block(&mut self) -> &mut BlockFlow {
         &mut self.block_flow
     }
diff --git a/components/layout/table_wrapper.rs b/components/layout/table_wrapper.rs
index 1c9c049356e..65ecc07d3ab 100644
--- a/components/layout/table_wrapper.rs
+++ b/components/layout/table_wrapper.rs
@@ -333,10 +333,6 @@ impl Flow for TableWrapperFlow {
         FlowClass::TableWrapper
     }
 
-    fn as_mut_table_wrapper(&mut self) -> &mut TableWrapperFlow {
-        self
-    }
-
     fn as_table_wrapper(&self) -> &TableWrapperFlow {
         self
     }
diff --git a/components/layout/traversal.rs b/components/layout/traversal.rs
index 6d44fcfc5e4..e968c184341 100644
--- a/components/layout/traversal.rs
+++ b/components/layout/traversal.rs
@@ -25,12 +25,6 @@ pub struct RecalcStyleAndConstructFlows<'a> {
 }
 
 impl<'a> RecalcStyleAndConstructFlows<'a> {
-    pub fn layout_context(&self) -> &LayoutContext<'a> {
-        &self.context
-    }
-}
-
-impl<'a> RecalcStyleAndConstructFlows<'a> {
     /// Creates a traversal context, taking ownership of the shared layout context.
     pub fn new(context: LayoutContext<'a>) -> Self {
         RecalcStyleAndConstructFlows { context: context }