Bug 1573268 - Convert layout.css.ruby.intercharacter.enabled to static pref. r=njn

Converts layout.css.ruby.intercharacter.enabled to a static pref and removes the associated function nsLayoutUtils::IsInterCharacterRubyEnabled(). Also removes the macro INTERCHARACTER_RUBY_ENABLED_PREF_NAME, since it was only being used to add the varcache pref.

Differential Revision: https://phabricator.services.mozilla.com/D41653

--HG--
extra : moz-landing-system : lando

layout/base/nsLayoutUtils.cpp

@@ -167,9 +167,6 @@ using namespace mozilla::gfx;
 using mozilla::dom::HTMLMediaElement_Binding::HAVE_METADATA;
 using mozilla::dom::HTMLMediaElement_Binding::HAVE_NOTHING;
 
-#define INTERCHARACTER_RUBY_ENABLED_PREF_NAME \
-  "layout.css.ruby.intercharacter.enabled"
-
 // The time in number of frames that we estimate for a refresh driver
 // to be quiescent
 #define DEFAULT_QUIESCENT_FRAMES 2
@@ -557,19 +554,6 @@ bool nsLayoutUtils::GPUImageScalingEnabled() {
   return sGPUImageScalingEnabled;
 }
 
-bool nsLayoutUtils::IsInterCharacterRubyEnabled() {
-  static bool sInterCharacterRubyEnabled;
-  static bool sInterCharacterRubyEnabledPrefCached = false;
-
-  if (!sInterCharacterRubyEnabledPrefCached) {
-    sInterCharacterRubyEnabledPrefCached = true;
-    Preferences::AddBoolVarCache(&sInterCharacterRubyEnabled,
-                                 INTERCHARACTER_RUBY_ENABLED_PREF_NAME, false);
-  }
-
-  return sInterCharacterRubyEnabled;
-}
-
 void nsLayoutUtils::UnionChildOverflow(nsIFrame* aFrame,
                                        nsOverflowAreas& aOverflowAreas,
                                        FrameChildListIDs aSkipChildLists) {

layout/base/nsLayoutUtils.h

@@ -2397,11 +2397,6 @@ class nsLayoutUtils {
    */
   static bool GPUImageScalingEnabled();
 
-  /**
-   * Checks whether support for inter-character ruby is enabled.
-   */
-  static bool IsInterCharacterRubyEnabled();
-
   static bool InterruptibleReflowEnabled() {
     return sInterruptibleReflowEnabled;
   }

layout/generic/nsRubyFrame.cpp

@@ -12,6 +12,7 @@
 #include "mozilla/ComputedStyle.h"
 #include "mozilla/Maybe.h"
 #include "mozilla/PresShell.h"
+#include "mozilla/StaticPrefs_layout.h"
 #include "mozilla/WritingModes.h"
 #include "nsLineLayout.h"
 #include "nsPresContext.h"
@@ -312,7 +313,7 @@ void nsRubyFrame::ReflowSegment(nsPresContext* aPresContext,
 
     LogicalPoint position(lineWM);
     if (side.isSome()) {
-      if (nsLayoutUtils::IsInterCharacterRubyEnabled() &&
+      if (StaticPrefs::layout_css_ruby_intercharacter_enabled() &&
           rtcWM.IsVerticalRL() &&
           lineWM.GetInlineDir() == WritingMode::eInlineLTR) {
         // Inter-character ruby annotations are only supported for vertical-rl

modules/libpref/init/StaticPrefList.yaml

@@ -4329,6 +4329,12 @@
   value: true
   mirror: always
 
+# Are inter-character ruby annotations enabled?
+- name: layout.css.ruby.intercharacter.enabled
+  type: bool
+  value: false
+  mirror: always
+
 - name: layout.css.scroll-behavior.damping-ratio
   type: AtomicFloat
   value: 1.0f

modules/libpref/init/all.js

@@ -2952,9 +2952,6 @@ pref("layout.css.scroll-behavior.spring-constant", "250.0");
 // at the greatest speed without overshooting.
 pref("layout.css.scroll-behavior.damping-ratio", "1.0");
 
-// Are inter-character ruby annotations enabled?
-pref("layout.css.ruby.intercharacter.enabled", false);
-
 // pref for which side vertical scrollbars should be on
 // 0 = end-side in UI direction
 // 1 = end-side in document/content direction