style: Update comments to no longer point to nsRuleNode.

There are a few mentions of nsRuleNode left but they are mostly
historical references so it makes sense to keep them.

Differential Revision: https://phabricator.services.mozilla.com/D5505

components/style/properties/gecko.mako.rs

@@ -2403,7 +2403,8 @@ fn static_assert() {
     /// Calculates the constrained and unconstrained font sizes to be inherited
     /// from the parent.
     ///
-    /// See ComputeScriptLevelSize in Gecko's nsRuleNode.cpp
+    /// This is a port of Gecko's old ComputeScriptLevelSize function:
+    /// https://dxr.mozilla.org/mozilla-central/rev/35fbf14b9/layout/style/nsRuleNode.cpp#3197-3254
     ///
     /// scriptlevel is a property that affects how font-size is inherited. If scriptlevel is
     /// +1, for example, it will inherit as the script size multiplier times
@@ -2511,17 +2512,18 @@ fn static_assert() {
             = self.calculate_script_level_size(parent, device);
         if adjusted_size.0 != parent.gecko.mSize ||
            adjusted_unconstrained_size.0 != parent.gecko.mScriptUnconstrainedSize {
-            // This is incorrect. When there is both a keyword size being inherited
-            // and a scriptlevel change, we must handle the keyword size the same
-            // way we handle em units. This complicates things because we now have
-            // to keep track of the adjusted and unadjusted ratios in the kw font size.
-            // This only affects the use case of a generic font being used in MathML.
+            // FIXME(Manishearth): This is incorrect. When there is both a
+            // keyword size being inherited and a scriptlevel change, we must
+            // handle the keyword size the same way we handle em units. This
+            // complicates things because we now have to keep track of the
+            // adjusted and unadjusted ratios in the kw font size. This only
+            // affects the use case of a generic font being used in MathML.
             //
-            // If we were to fix this I would prefer doing it by removing the
-            // ruletree walk on the Gecko side in nsRuleNode::SetGenericFont
-            // and instead using extra bookkeeping in the mSize and mScriptUnconstrainedSize
-            // values, and reusing those instead of font_size_keyword.
-
+            // If we were to fix this I would prefer doing it not doing
+            // something like the ruletree walk that Gecko used to do in
+            // nsRuleNode::SetGenericFont and instead using extra bookkeeping in
+            // the mSize and mScriptUnconstrainedSize values, and reusing those
+            // instead of font_size_keyword.
 
             // In the case that MathML has given us an adjusted size, apply it.
             // Keep track of the unconstrained adjusted size.

components/style/rule_tree/mod.rs

@@ -1200,9 +1200,6 @@ impl StrongRuleNode {
         }
     }
 
-    /// Implementation of `nsRuleNode::HasAuthorSpecifiedRules` for Servo rule
-    /// nodes.
-    ///
     /// Returns true if any properties specified by `rule_type_mask` was set by
     /// an author rule.
     #[cfg(feature = "gecko")]

components/style/values/specified/font.rs

@@ -746,7 +746,12 @@ impl ToComputedValue for KeywordSize {
     fn to_computed_value(&self, cx: &Context) -> NonNegativeLength {
         use context::QuirksMode;
         use values::specified::length::au_to_int_px;
-        // Data from nsRuleNode.cpp in Gecko
+
+        // The tables in this function are originally from
+        // nsRuleNode::CalcFontPointSize in Gecko:
+        //
+        // https://dxr.mozilla.org/mozilla-central/rev/35fbf14b9/layout/style/nsRuleNode.cpp#3262-3336
+
         // Mapping from base size and HTML size to pixels
         // The first index is (base_size - 9), the second is the
         // HTML size. "0" is CSS keyword xx-small, not HTML size 0,
@@ -765,9 +770,6 @@ impl ToComputedValue for KeywordSize {
             [9, 10, 13, 16, 18, 24, 32, 48],
         ];
 
-        // Data from nsRuleNode.cpp in Gecko
-        // (https://dxr.mozilla.org/mozilla-central/rev/35fbf14b9/layout/style/nsRuleNode.cpp#3303)
-        //
         // This table gives us compatibility with WinNav4 for the default fonts only.
         // In WinNav4, the default fonts were:
         //