Perf: remove unnecessary shadows and mask views

App/Browser View/BrowserView.swift

@@ -149,6 +149,10 @@ class BrowserView: UIView
                 autocompleteView.layer.cornerRadius = 8.0
                 autocompleteView.layer.masksToBounds = true
                 
+                let shadowPath = UIBezierPath(roundedRect: autocompleteView.bounds,
+                                              cornerRadius: autocompleteView.layer.cornerRadius)
+                autocompleteView.layer.shadowPath = shadowPath.cgPath
+                
                 if let toolbarView = toolbarView, let urlBar = toolbarView.urlBar {
                     let urlFrame = self.convert(urlBar.frame, from: urlBar.superview)
                     autocompleteView.frame = CGRect(
@@ -158,6 +162,9 @@ class BrowserView: UIView
                         height: bounds.height / 2.5
                     )
                 }
+            } else {
+                autocompleteView.layer.cornerRadius = 0.0
+                autocompleteView.layer.shadowOpacity = 0.0
             }
         }
         

App/Common UI/ReliefButton.swift

@@ -65,6 +65,8 @@ class ReliefButton: UIButton
         backgroundView.layer.masksToBounds = true
         backgroundView.layer.borderWidth = Self.borderWidth
         backgroundView.layer.cornerCurve = .continuous
+        backgroundView.layer.shouldRasterize = true
+        backgroundView.layer.rasterizationScale = UIScreen.main.scale
         addSubview(backgroundView)
         
         traitCollectionDidChange(nil)
@@ -151,5 +153,8 @@ class ReliefButton: UIButton
         }
         
         shadowView.frame = backgroundView.frame
+        
+        let shadowPath = UIBezierPath(roundedRect: shadowView.bounds, cornerRadius: Self.cornerRadius)
+        shadowView.layer.shadowPath = shadowPath.cgPath
     }
 }

App/Common UI/SegmentedReliefButton.swift

@@ -14,7 +14,6 @@ class SegmentedReliefButton: ReliefButton
         didSet  { children.forEach { addSubview($0) }; setNeedsLayout() }
     }
     
-    private let backgroundMaskView = UIView(frame: .zero)
     private let backgroundsContainerView = UIView(frame: .zero)
     private var childrenHighlighObservations: [NSKeyValueObservation] = []
     
@@ -22,12 +21,10 @@ class SegmentedReliefButton: ReliefButton
         super.init()
         self.children = children
         
-        backgroundMaskView.backgroundColor = .black
-        backgroundMaskView.layer.masksToBounds = true
-        backgroundMaskView.layer.cornerRadius = Self.cornerRadius - Self.borderWidth
-        
         backgroundsContainerView.clipsToBounds = true
-        backgroundsContainerView.mask = backgroundMaskView
+        backgroundsContainerView.layer.cornerRadius = Self.cornerRadius - Self.borderWidth
+        
+        constrainedToSquare = false
         
         addSubview(backgroundsContainerView)
     }
@@ -57,10 +54,7 @@ class SegmentedReliefButton: ReliefButton
         super.layoutSubviews()
         
         backgroundView.colors = [ .clear ]
-        backgroundView.frame = bounds
-        shadowView.frame = bounds
         
-        backgroundMaskView.frame = backgroundView.frame.insetBy(dx: 1.0, dy: 1.0)
         backgroundsContainerView.frame = backgroundView.frame
         
         childrenHighlighObservations.removeAll()

App/Titlebar and URL Bar/ToolbarView.swift

@@ -48,6 +48,9 @@ class ToolbarView: UIView
     {
         super.layoutSubviews()
         
+        let shadowPath = UIBezierPath(rect: bounds)
+        layer.shadowPath = shadowPath.cgPath
+
         backgroundView.frame = bounds
         
         var containerBounds = bounds

App/Titlebar and URL Bar/URLBar.swift

@@ -41,6 +41,7 @@ class URLBar: ReliefButton
         super.init()
         
         backgroundColor = .clear
+        constrainedToSquare = false
         
         backgroundView.addSubview(progressIndicatorView)