Fix some clippy warnings in components/gfx and components/script (#32215)

* clippy: Squish warnings and errors in gfx

warning: redundant closure (gfx/font.rs:415:18)

warning: useless conversion to the same type (gfx/font.rs:534:9)

warning: the following explicit lifetimes could be elided: 'a (gfx/font.rs:619:16)

error: this loop never actually loops (gfx/font_cache_thread.rs:112:9)

warning: this expression creates a reference which is immediately dereferenced by the compiler  (gfx/font_cache_thread.rs:229:51)

warning: redundant closure (gfx/font_cache_thread.rs:551:18)

3 instances of:
warning: casting integer literal to `f64` is unnecessary (gfx/platform/freetype/font_list.rs:271-273)

* clippy: methods called `from_*` usually take no `self`

It reports that by standard convention, from_* methods should not take any `&self` parameter

* clippy: you should consider adding a `Default` implementation

It reports that public types with a pub fn new() -> Self should have a Default implementation since they can be constructed without arguments

* clippy: casting to the same type is unnecessary (`f32` -> `f32`)

* clippy: use of `unwrap_or_else` to construct default value

* clippy: methods called `is_*` usually take `self` by mutable reference or `self` by reference or no `self`

* clippy: manual `!RangeInclusive::contains` implementation

contains expresses the intent better and has less failure modes (such as fencepost errors or using || instead of &&)

* clippy: this function has an empty `#[must_use]` attribute, but returns a type already marked as `#[must_use]`

* clippy: Fix some new warnings

warning: this `if` statement can be collapsed (gfx/font.rs:468:130)

warning: this lifetime isn't used in the impl (gfx/platform/freetype/font.rs:341:6)

warning: field assignment outside of initializer for an instance created with Default::default() (compositor.rs:881:17)

components/gfx/font.rs

@@ -443,7 +443,7 @@ impl FontGroup {
             .font_family
             .families
             .iter()
-            .map(|family| FontGroupFamily::new(family))
+            .map(FontGroupFamily::new)
             .collect();
 
         FontGroup {
@@ -465,10 +465,8 @@ impl FontGroup {
         let should_look_for_small_caps = self.descriptor.variant == font_variant_caps::T::SmallCaps &&
             codepoint.is_ascii_lowercase();
         let font_or_synthesized_small_caps = |font: FontRef| {
-            if should_look_for_small_caps {
-                if font.synthesized_small_caps.is_some() {
-                    return font.synthesized_small_caps.clone();
-                }
+            if should_look_for_small_caps && font.synthesized_small_caps.is_some() {
+                return font.synthesized_small_caps.clone();
             }
             Some(font)
         };
@@ -565,7 +563,6 @@ impl FontGroup {
             .chain(fallback_font_families(codepoint).into_iter().map(|family| {
                 FontFamilyDescriptor::new(FontFamilyName::from(family), FontSearchScope::Local)
             }))
-            .into_iter()
             .filter_map(|family_descriptor| {
                 FontGroupFamily {
                     family_descriptor,
@@ -646,11 +643,11 @@ impl FontGroupFamily {
             .next()
     }
 
-    fn members<'a, S: FontSource>(
-        &'a mut self,
+    fn members<S: FontSource>(
+        &mut self,
         font_descriptor: &FontDescriptor,
         font_context: &FontContext<S>,
-    ) -> impl Iterator<Item = &mut FontGroupFamilyMember> + 'a {
+    ) -> impl Iterator<Item = &mut FontGroupFamilyMember> {
         let family_descriptor = &self.family_descriptor;
         let members = self.members.get_or_insert_with(|| {
             font_context

components/gfx/font_cache_thread.rs

@@ -108,7 +108,7 @@ impl FontTemplates {
         // If a request is made for a font family that exists,
         // pick the first valid font in the family if we failed
         // to find an exact match for the descriptor.
-        for template in &mut self.templates.iter() {
+        if let Some(template) = self.templates.first() {
             return vec![template.clone()];
         }
 
@@ -231,7 +231,7 @@ impl FontCache {
                             .font_data
                             .entry(identifier)
                             .or_insert_with(|| font_template.data());
-                        let _ = bytes_sender.send(&data);
+                        let _ = bytes_sender.send(data);
                     }
                 },
                 Command::GetFontInstance(identifier, pt_size, flags, result) => {
@@ -557,10 +557,7 @@ impl From<&FontFaceRuleData> for CSSFontFaceDescriptors {
                 ),
             }
         }
-        let style = rule_data
-            .style
-            .as_ref()
-            .map(|style| style_to_computed(style));
+        let style = rule_data.style.as_ref().map(style_to_computed);
         let unicode_range = rule_data
             .unicode_range
             .as_ref()

components/gfx/platform/freetype/font.rs

@@ -338,7 +338,7 @@ impl PlatformFontMethods for PlatformFont {
     }
 }
 
-impl<'a> PlatformFont {
+impl PlatformFont {
     fn set_char_size(face: FT_Face, pt_size: Au) -> Result<(), &'static str> {
         let char_size = pt_size.to_f64_px() * 64.0 + 0.5;
 

components/gfx/platform/freetype/font_list.rs

@@ -268,9 +268,9 @@ fn font_weight_from_fontconfig_pattern(pattern: *mut FcPattern) -> Option<FontWe
 
     let mapping = [
         (0., 0.),
-        (FC_WEIGHT_REGULAR as f64, 400 as f64),
-        (FC_WEIGHT_BOLD as f64, 700 as f64),
-        (FC_WEIGHT_EXTRABLACK as f64, 1000 as f64),
+        (FC_WEIGHT_REGULAR as f64, 400_f64),
+        (FC_WEIGHT_BOLD as f64, 700_f64),
+        (FC_WEIGHT_EXTRABLACK as f64, 1000_f64),
     ];
 
     let mapped_weight = map_platform_values_to_style_values(&mapping, weight as f64);