Bug 1533428 - patch 7 - Create a FontFamily type that wraps either a gfxFontFamily pointer or a mozilla::fontlist::Family pointer (to be used by the shared font list), and use this in various places where we need to pass families around. r=jwatt

Differential Revision: https://phabricator.services.mozilla.com/D22934

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

gfx/thebes/gfxDWriteFontList.cpp

@@ -837,12 +837,12 @@ gfxDWriteFontList::gfxDWriteFontList() : mForceGDIClassicMaxFontSize(0.0) {}
 //   I/O strain during cold startup due to dwrite caching bugs.  Default to
 //   Arial to avoid this.
 
-gfxFontFamily* gfxDWriteFontList::GetDefaultFontForPlatform(
+FontFamily gfxDWriteFontList::GetDefaultFontForPlatform(
     const gfxFontStyle* aStyle) {
   // try Arial first
   gfxFontFamily* ff;
   if ((ff = FindFamily(NS_LITERAL_CSTRING("Arial")))) {
-    return ff;
+    return FontFamily(ff);
   }
 
   // otherwise, use local default
@@ -854,11 +854,11 @@ gfxFontFamily* gfxDWriteFontList::GetDefaultFontForPlatform(
   if (status) {
     ff = FindFamily(NS_ConvertUTF16toUTF8(ncm.lfMessageFont.lfFaceName));
     if (ff) {
-      return ff;
+      return FontFamily(ff);
     }
   }
 
-  return nullptr;
+  return FontFamily();
 }
 
 gfxFontEntry* gfxDWriteFontList::LookupLocalFont(
@@ -1417,7 +1417,7 @@ IFACEMETHODIMP DWriteFontFallbackRenderer::DrawGlyphRun(
 
 gfxFontEntry* gfxDWriteFontList::PlatformGlobalFontFallback(
     const uint32_t aCh, Script aRunScript, const gfxFontStyle* aMatchStyle,
-    gfxFontFamily** aMatchedFamily) {
+    FontFamily* aMatchedFamily) {
   HRESULT hr;
 
   RefPtr<IDWriteFactory> dwFactory = Factory::GetDWriteFactory();
@@ -1477,7 +1477,7 @@ gfxFontEntry* gfxDWriteFontList::PlatformGlobalFontFallback(
     gfxFontEntry* fontEntry;
     fontEntry = family->FindFontForStyle(*aMatchStyle);
     if (fontEntry && fontEntry->HasCharacter(aCh)) {
-      *aMatchedFamily = family;
+      *aMatchedFamily = FontFamily(family);
       return fontEntry;
     }
     Telemetry::Accumulate(Telemetry::BAD_FALLBACK_FONT, true);

gfx/thebes/gfxDWriteFontList.h

@@ -404,14 +404,14 @@ class gfxDWriteFontList : public gfxPlatformFontList {
                                       FontListSizes* aSizes) const;
 
  protected:
-  virtual gfxFontFamily* GetDefaultFontForPlatform(
-      const gfxFontStyle* aStyle) override;
+  FontFamily GetDefaultFontForPlatform(const gfxFontStyle* aStyle) override;
 
   // attempt to use platform-specific fallback for the given character,
   // return null if no usable result found
-  gfxFontEntry* PlatformGlobalFontFallback(
-      const uint32_t aCh, Script aRunScript, const gfxFontStyle* aMatchStyle,
-      gfxFontFamily** aMatchedFamily) override;
+  gfxFontEntry* PlatformGlobalFontFallback(const uint32_t aCh,
+                                           Script aRunScript,
+                                           const gfxFontStyle* aMatchStyle,
+                                           FontFamily* aMatchedFamily) override;
 
  private:
   friend class gfxDWriteFontFamily;

gfx/thebes/gfxFT2FontList.cpp

@@ -1505,7 +1505,7 @@ searchDone:
   return fe;
 }
 
-gfxFontFamily* gfxFT2FontList::GetDefaultFontForPlatform(
+FontFamily gfxFT2FontList::GetDefaultFontForPlatform(
     const gfxFontStyle* aStyle) {
   gfxFontFamily* ff = nullptr;
 #if defined(MOZ_WIDGET_ANDROID)
@@ -1515,7 +1515,7 @@ gfxFontFamily* gfxFT2FontList::GetDefaultFontForPlatform(
   }
 #endif
   /* TODO: what about Qt or other platforms that may use this? */
-  return ff;
+  return FontFamily(ff);
 }
 
 gfxFontEntry* gfxFT2FontList::MakePlatformFont(const nsACString& aFontName,

gfx/thebes/gfxFT2FontList.h

@@ -176,8 +176,7 @@ class gfxFT2FontList : public gfxPlatformFontList {
 
   void FindFontsInDir(const nsCString& aDir, FontNameCache* aFNC);
 
-  virtual gfxFontFamily* GetDefaultFontForPlatform(
-      const gfxFontStyle* aStyle) override;
+  FontFamily GetDefaultFontForPlatform(const gfxFontStyle* aStyle) override;
 
   nsTHashtable<nsCStringHashKey> mSkipSpaceLookupCheckFamilies;
 

gfx/thebes/gfxFcPlatformFontList.cpp

@@ -1739,7 +1739,7 @@ void gfxFcPlatformFontList::GetFontList(nsAtom* aLangGroup,
   if (serif) aListOfFonts.InsertElementAt(0, NS_LITERAL_STRING("serif"));
 }
 
-gfxFontFamily* gfxFcPlatformFontList::GetDefaultFontForPlatform(
+FontFamily gfxFcPlatformFontList::GetDefaultFontForPlatform(
     const gfxFontStyle* aStyle) {
   // Get the default font by using a fake name to retrieve the first
   // scalable font that fontconfig suggests for the given language.
@@ -1749,7 +1749,7 @@ gfxFontFamily* gfxFcPlatformFontList::GetDefaultFontForPlatform(
   if (prefFonts && !prefFonts->IsEmpty()) {
     return (*prefFonts)[0];
   }
-  return nullptr;
+  return FontFamily();
 }
 
 gfxFontEntry* gfxFcPlatformFontList::LookupLocalFont(
@@ -2030,7 +2030,7 @@ void gfxFcPlatformFontList::AddGenericFonts(
   NS_ASSERTION(prefFonts, "null generic font list");
   aFamilyList.SetCapacity(aFamilyList.Length() + prefFonts->Length());
   for (auto& f : *prefFonts) {
-    aFamilyList.AppendElement(FamilyAndGeneric(f.get(), aGenericType));
+    aFamilyList.AppendElement(FamilyAndGeneric(f, aGenericType));
   }
 }
 

gfx/thebes/gfxFcPlatformFontList.h

@@ -349,8 +349,7 @@ class gfxFcPlatformFontList : public gfxPlatformFontList {
 
   static void CheckFontUpdates(nsITimer* aTimer, void* aThis);
 
-  virtual gfxFontFamily* GetDefaultFontForPlatform(
-      const gfxFontStyle* aStyle) override;
+  FontFamily GetDefaultFontForPlatform(const gfxFontStyle* aStyle) override;
 
   gfxFontFamily* CreateFontFamily(const nsACString& aName) const override;
 

gfx/thebes/gfxFontEntry.h

@@ -45,7 +45,11 @@ class nsAtom;
 
 namespace mozilla {
 class SVGContextPaint;
-};
+namespace fontlist {
+struct Family;
+struct Face;
+}  // namespace fontlist
+}  // namespace mozilla
 
 #define NO_FONT_LANGUAGE_OVERRIDE 0
 
@@ -906,19 +910,61 @@ class gfxFontFamily {
   };
 };
 
+// Wrapper for either a mozilla::fontlist::Family in the shared font list or an
+// unshared gfxFontFamily that belongs just to the current process. This does
+// not own a reference, it just wraps a raw pointer and records the type.
+struct FontFamily {
+  FontFamily() : mUnshared(nullptr), mIsShared(false) {}
+
+  FontFamily(const FontFamily& aOther) = default;
+
+  explicit FontFamily(gfxFontFamily* aFamily)
+      : mUnshared(aFamily), mIsShared(false) {}
+
+  explicit FontFamily(mozilla::fontlist::Family* aFamily)
+      : mShared(aFamily), mIsShared(true) {}
+
+  bool operator==(const FontFamily& aOther) const {
+    return mIsShared == aOther.mIsShared &&
+           (mIsShared ? mShared == aOther.mShared
+                      : mUnshared == aOther.mUnshared);
+  }
+
+  bool IsNull() const { return mIsShared ? !mShared : !mUnshared; }
+
+  union {
+    gfxFontFamily* mUnshared;
+    mozilla::fontlist::Family* mShared;
+  };
+  bool mIsShared;
+};
+
 // Struct used in the gfxFontGroup font list to keep track of a font family
 // together with the CSS generic (if any) that was mapped to it in this
 // particular case (so it can be reported to the DevTools font inspector).
 struct FamilyAndGeneric final {
   FamilyAndGeneric()
-      : mFamily(nullptr), mGeneric(mozilla::FontFamilyType::eFamily_none) {}
+      : mFamily(), mGeneric(mozilla::FontFamilyType::eFamily_none) {}
   FamilyAndGeneric(const FamilyAndGeneric& aOther)
       : mFamily(aOther.mFamily), mGeneric(aOther.mGeneric) {}
   explicit FamilyAndGeneric(
       gfxFontFamily* aFamily,
       mozilla::FontFamilyType aGeneric = mozilla::FontFamilyType::eFamily_none)
       : mFamily(aFamily), mGeneric(aGeneric) {}
-  gfxFontFamily* mFamily;
+  explicit FamilyAndGeneric(
+      mozilla::fontlist::Family* aFamily,
+      mozilla::FontFamilyType aGeneric = mozilla::FontFamilyType::eFamily_none)
+      : mFamily(aFamily), mGeneric(aGeneric) {}
+  explicit FamilyAndGeneric(
+      const FontFamily& aFamily,
+      mozilla::FontFamilyType aGeneric = mozilla::FontFamilyType::eFamily_none)
+      : mFamily(aFamily), mGeneric(aGeneric) {}
+
+  bool operator==(const FamilyAndGeneric& aOther) const {
+    return (mFamily == aOther.mFamily && mGeneric == aOther.mGeneric);
+  }
+
+  FontFamily mFamily;
   mozilla::FontFamilyType mGeneric;
 };
 

gfx/thebes/gfxGDIFontList.cpp

@@ -843,7 +843,7 @@ bool gfxGDIFontList::FindAndAddFamilies(const nsACString& aFamily,
                                                  aStyle, aDevToCssSize);
 }
 
-gfxFontFamily* gfxGDIFontList::GetDefaultFontForPlatform(
+FontFamily gfxGDIFontList::GetDefaultFontForPlatform(
     const gfxFontStyle* aStyle) {
   gfxFontFamily* ff = nullptr;
 
@@ -855,7 +855,7 @@ gfxFontFamily* gfxGDIFontList::GetDefaultFontForPlatform(
   if (status) {
     ff = FindFamily(NS_ConvertUTF16toUTF8(ncm.lfMessageFont.lfFaceName));
     if (ff) {
-      return ff;
+      return FontFamily(ff);
     }
   }
 
@@ -866,7 +866,7 @@ gfxFontFamily* gfxGDIFontList::GetDefaultFontForPlatform(
     ff = FindFamily(NS_ConvertUTF16toUTF8(logFont.lfFaceName));
   }
 
-  return ff;
+  return FontFamily(ff);
 }
 
 void gfxGDIFontList::AddSizeOfExcludingThis(MallocSizeOf aMallocSizeOf,

gfx/thebes/gfxGDIFontList.h

@@ -323,8 +323,7 @@ class gfxGDIFontList : public gfxPlatformFontList {
                                       FontListSizes* aSizes) const;
 
  protected:
-  virtual gfxFontFamily* GetDefaultFontForPlatform(
-      const gfxFontStyle* aStyle) override;
+  FontFamily GetDefaultFontForPlatform(const gfxFontStyle* aStyle) override;
 
  private:
   friend class gfxWindowsPlatform;

gfx/thebes/gfxMacPlatformFontList.h

@@ -178,7 +178,7 @@ class gfxMacPlatformFontList : public gfxPlatformFontList {
       InfallibleTArray<mozilla::dom::SystemFontListEntry>* aList);
 
  protected:
-  gfxFontFamily* GetDefaultFontForPlatform(const gfxFontStyle* aStyle) override;
+  FontFamily GetDefaultFontForPlatform(const gfxFontStyle* aStyle) override;
 
  private:
   friend class gfxPlatformMac;
@@ -204,9 +204,10 @@ class gfxMacPlatformFontList : public gfxPlatformFontList {
 
   // attempt to use platform-specific fallback for the given character
   // return null if no usable result found
-  gfxFontEntry* PlatformGlobalFontFallback(
-      const uint32_t aCh, Script aRunScript, const gfxFontStyle* aMatchStyle,
-      gfxFontFamily** aMatchedFamily) override;
+  gfxFontEntry* PlatformGlobalFontFallback(const uint32_t aCh,
+                                           Script aRunScript,
+                                           const gfxFontStyle* aMatchStyle,
+                                           FontFamily* aMatchedFamily) override;
 
   bool UsesSystemFallback() override { return true; }
 

gfx/thebes/gfxMacPlatformFontList.mm

@@ -1283,7 +1283,7 @@ void gfxMacPlatformFontList::RegisteredFontsChangedNotificationCallback(
 gfxFontEntry* gfxMacPlatformFontList::PlatformGlobalFontFallback(const uint32_t aCh,
                                                                  Script aRunScript,
                                                                  const gfxFontStyle* aMatchStyle,
-                                                                 gfxFontFamily** aMatchedFamily) {
+                                                                 FontFamily* aMatchedFamily) {
   CFStringRef str;
   UniChar ch[2];
   CFIndex length = 1;
@@ -1335,7 +1335,7 @@ gfxFontEntry* gfxMacPlatformFontList::PlatformGlobalFontFallback(const uint32_t
         fontEntry = family->FindFontForStyle(*aMatchStyle);
         if (fontEntry) {
           if (fontEntry->HasCharacter(aCh)) {
-            *aMatchedFamily = family;
+            *aMatchedFamily = FontFamily(family);
           } else {
             fontEntry = nullptr;
             cantUseFallbackFont = true;
@@ -1358,14 +1358,14 @@ gfxFontEntry* gfxMacPlatformFontList::PlatformGlobalFontFallback(const uint32_t
   return fontEntry;
 }
 
-gfxFontFamily* gfxMacPlatformFontList::GetDefaultFontForPlatform(const gfxFontStyle* aStyle) {
+FontFamily gfxMacPlatformFontList::GetDefaultFontForPlatform(const gfxFontStyle* aStyle) {
   nsAutoreleasePool localPool;
 
   NSString* defaultFamily = [[NSFont userFontOfSize:aStyle->size] familyName];
   nsAutoString familyName;
 
   GetStringForNSString(defaultFamily, familyName);
-  return FindFamily(NS_ConvertUTF16toUTF8(familyName));
+  return FontFamily(FindFamily(NS_ConvertUTF16toUTF8(familyName)));
 }
 
 int32_t gfxMacPlatformFontList::AppleWeightToCSSWeight(int32_t aAppleWeight) {

gfx/thebes/gfxPlatformFontList.cpp

@@ -355,7 +355,6 @@ nsresult gfxPlatformFontList::InitFontList() {
   }
   mFaceNameListsInitialized = false;
   ClearLangGroupPrefFonts();
-  mReplacementCharFallbackFamily = nullptr;
   CancelLoader();
 
   // initialize ranges of characters for which system-wide font search should be
@@ -568,8 +567,12 @@ gfxFontEntry* gfxPlatformFontList::SystemFindFontForChar(
   // encoding errors: just use cached family from last time U+FFFD was seen.
   // This helps speed up pages with lots of encoding errors, binary-as-text,
   // etc.
-  if (aCh == 0xFFFD && mReplacementCharFallbackFamily) {
-    fontEntry = mReplacementCharFallbackFamily->FindFontForStyle(*aStyle);
+  if (aCh == 0xFFFD) {
+    if (!mReplacementCharFallbackFamily.mIsShared &&
+        mReplacementCharFallbackFamily.mUnshared) {
+      fontEntry =
+          mReplacementCharFallbackFamily.mUnshared->FindFontForStyle(*aStyle);
+    }
 
     // this should never fail, as we must have found U+FFFD in order to set
     // mReplacementCharFallbackFamily at all, but better play it safe
@@ -582,7 +585,7 @@ gfxFontEntry* gfxPlatformFontList::SystemFindFontForChar(
 
   // search commonly available fonts
   bool common = true;
-  gfxFontFamily* fallbackFamily = nullptr;
+  FontFamily fallbackFamily;
   fontEntry =
       CommonFontFallback(aCh, aNextCh, aRunScript, aStyle, &fallbackFamily);
 
@@ -613,7 +616,7 @@ gfxFontEntry* gfxPlatformFontList::SystemFindFontForChar(
   // no match? add to set of non-matching codepoints
   if (!fontEntry) {
     mCodepointsWithNoFonts.set(aCh);
-  } else if (aCh == 0xFFFD && fontEntry && fallbackFamily) {
+  } else if (aCh == 0xFFFD && fontEntry) {
     mReplacementCharFallbackFamily = fallbackFamily;
   }
 
@@ -638,7 +641,7 @@ gfxFontEntry* gfxPlatformFontList::SystemFindFontForChar(
 
 gfxFontEntry* gfxPlatformFontList::CommonFontFallback(
     uint32_t aCh, uint32_t aNextCh, Script aRunScript,
-    const gfxFontStyle* aMatchStyle, gfxFontFamily** aMatchedFamily) {
+    const gfxFontStyle* aMatchStyle, FontFamily* aMatchedFamily) {
   AutoTArray<const char*, NUM_FALLBACK_FONTS> defaultFallbacks;
   gfxPlatform::GetPlatform()->GetCommonFallbackFonts(aCh, aNextCh, aRunScript,
                                                      defaultFallbacks);
@@ -649,7 +652,7 @@ gfxFontEntry* gfxPlatformFontList::CommonFontFallback(
     if (fallback) {
       fallback->FindFontForChar(&data);
       if (data.mBestMatch) {
-        *aMatchedFamily = fallback;
+        *aMatchedFamily = FontFamily(fallback);
         return data.mBestMatch;
       }
     }
@@ -659,7 +662,7 @@ gfxFontEntry* gfxPlatformFontList::CommonFontFallback(
 
 gfxFontEntry* gfxPlatformFontList::GlobalFontFallback(
     const uint32_t aCh, Script aRunScript, const gfxFontStyle* aMatchStyle,
-    uint32_t& aCmapCount, gfxFontFamily** aMatchedFamily) {
+    uint32_t& aCmapCount, FontFamily* aMatchedFamily) {
   bool useCmaps = IsFontFamilyWhitelistActive() ||
                   gfxPlatform::GetPlatform()->UseCmapsDuringSystemFallback();
   if (!useCmaps) {
@@ -686,7 +689,7 @@ gfxFontEntry* gfxPlatformFontList::GlobalFontFallback(
   }
 
   aCmapCount = data.mCmapsTested;
-  *aMatchedFamily = data.mMatchedFamily;
+  *aMatchedFamily = FontFamily(data.mMatchedFamily);
 
   return data.mBestMatch;
 }
@@ -995,7 +998,7 @@ void gfxPlatformFontList::AddGenericFonts(
   if (!prefFonts->IsEmpty()) {
     aFamilyList.SetCapacity(aFamilyList.Length() + prefFonts->Length());
     for (auto& f : *prefFonts) {
-      aFamilyList.AppendElement(FamilyAndGeneric(f.get(), aGenericType));
+      aFamilyList.AppendElement(FamilyAndGeneric(f, aGenericType));
     }
   }
 }
@@ -1307,16 +1310,16 @@ mozilla::FontFamilyType gfxPlatformFontList::GetDefaultGeneric(
   return eFamily_serif;
 }
 
-gfxFontFamily* gfxPlatformFontList::GetDefaultFont(const gfxFontStyle* aStyle) {
-  gfxFontFamily* family = GetDefaultFontForPlatform(aStyle);
-  if (family) {
+FontFamily gfxPlatformFontList::GetDefaultFont(const gfxFontStyle* aStyle) {
+  FontFamily family = GetDefaultFontForPlatform(aStyle);
+  if (!family.mIsShared && family.mUnshared) {
     return family;
   }
   // Something has gone wrong and we were unable to retrieve a default font
   // from the platform. (Likely the whitelist has blocked all potential
   // default fonts.) As a last resort, we return the first font listed in
   // mFontFamilies.
-  return mFontFamilies.Iter().Data();
+  return FontFamily(mFontFamilies.Iter().Data());
 }
 
 void gfxPlatformFontList::GetFontFamilyNames(

gfx/thebes/gfxPlatformFontList.h

@@ -100,7 +100,7 @@ class gfxPlatformFontList : public gfxFontInfoLoader {
   // For font family lists loaded from user preferences (prefs such as
   // font.name-list.<generic>.<langGroup>) that map CSS generics to
   // platform-specific font families.
-  typedef nsTArray<RefPtr<gfxFontFamily>> PrefFontList;
+  typedef nsTArray<FontFamily> PrefFontList;
 
   static gfxPlatformFontList* PlatformFontList() { return sPlatformFontList; }
 
@@ -184,7 +184,7 @@ class gfxPlatformFontList : public gfxFontInfoLoader {
   // pure virtual functions, to be provided by concrete subclasses
 
   // get the system default font family
-  gfxFontFamily* GetDefaultFont(const gfxFontStyle* aStyle);
+  FontFamily GetDefaultFont(const gfxFontStyle* aStyle);
 
   /**
    * Look up a font by name on the host platform.
@@ -396,7 +396,7 @@ class gfxPlatformFontList : public gfxFontInfoLoader {
                             gfxFloat aDevToCssSize = 1.0) {
     AutoTArray<FamilyAndGeneric, 1> families;
     return FindAndAddFamilies(aFamily, &families, aFlags, aStyle, aDevToCssSize)
-               ? families[0].mFamily
+               ? families[0].mFamily.mUnshared
                : nullptr;
   }
 
@@ -416,20 +416,20 @@ class gfxPlatformFontList : public gfxFontInfoLoader {
   gfxFontEntry* CommonFontFallback(uint32_t aCh, uint32_t aNextCh,
                                    Script aRunScript,
                                    const gfxFontStyle* aMatchStyle,
-                                   gfxFontFamily** aMatchedFamily);
+                                   FontFamily* aMatchedFamily);
 
   // Search fonts system-wide for a given character, null if not found.
   gfxFontEntry* GlobalFontFallback(const uint32_t aCh, Script aRunScript,
                                    const gfxFontStyle* aMatchStyle,
                                    uint32_t& aCmapCount,
-                                   gfxFontFamily** aMatchedFamily);
+                                   FontFamily* aMatchedFamily);
 
   // Platform-specific implementation of global font fallback, if any;
   // this may return nullptr in which case the default cmap-based fallback
   // will be performed.
   virtual gfxFontEntry* PlatformGlobalFontFallback(
       const uint32_t aCh, Script aRunScript, const gfxFontStyle* aMatchStyle,
-      gfxFontFamily** aMatchedFamily) {
+      FontFamily* aMatchedFamily) {
     return nullptr;
   }
 
@@ -514,8 +514,7 @@ class gfxPlatformFontList : public gfxFontInfoLoader {
       const FontEntryTable& aTable, mozilla::MallocSizeOf aMallocSizeOf);
 
   // Platform-specific helper for GetDefaultFont(...).
-  virtual gfxFontFamily* GetDefaultFontForPlatform(
-      const gfxFontStyle* aStyle) = 0;
+  virtual FontFamily GetDefaultFontForPlatform(const gfxFontStyle* aStyle) = 0;
 
   // Protects mFontFamilies.
   mozilla::Mutex mFontFamiliesMutex;
@@ -567,7 +566,7 @@ class gfxPlatformFontList : public gfxFontInfoLoader {
 
   // the family to use for U+FFFD fallback, to avoid expensive search every time
   // on pages with lots of problems
-  RefPtr<gfxFontFamily> mReplacementCharFallbackFamily;
+  FontFamily mReplacementCharFallbackFamily;
 
   // Sorted array of lowercased family names; use ContainsSorted to test
   nsTArray<nsCString> mBadUnderlineFamilyNames;

gfx/thebes/gfxTextRun.cpp

@@ -1734,7 +1734,7 @@ void gfxFontGroup::BuildFontList() {
 
   // build the fontlist from the specified families
   for (const auto& f : fonts) {
-    AddFamilyToFontList(f.mFamily, f.mGeneric);
+    AddFamilyToFontList(f.mFamily.mUnshared, f.mGeneric);
   }
 }
 
@@ -1897,12 +1897,12 @@ gfxFont* gfxFontGroup::GetDefaultFont() {
   }
 
   gfxPlatformFontList* pfl = gfxPlatformFontList::PlatformFontList();
-  gfxFontFamily* defaultFamily = pfl->GetDefaultFont(&mStyle);
-  NS_ASSERTION(defaultFamily,
+  FontFamily defaultFamily = pfl->GetDefaultFont(&mStyle);
+  NS_ASSERTION(!defaultFamily.mIsShared && defaultFamily.mUnshared,
                "invalid default font returned by GetDefaultFont");
 
-  if (defaultFamily) {
-    gfxFontEntry* fe = defaultFamily->FindFontForStyle(mStyle, true);
+  if (defaultFamily.mUnshared) {
+    gfxFontEntry* fe = defaultFamily.mUnshared->FindFontForStyle(mStyle, true);
     if (fe) {
       mDefaultFont = fe->FindOrMakeFont(&mStyle);
     }
@@ -3186,8 +3186,8 @@ gfxFont* gfxFontGroup::WhichPrefFontSupportsChar(uint32_t aCh,
     numPrefs = families->Length();
     for (j = 0; j < numPrefs; j++) {
       // look up the appropriate face
-      gfxFontFamily* family = (*families)[j];
-      if (!family) {
+      FontFamily family = (*families)[j];
+      if (family.IsNull()) {
         continue;
       }
 
@@ -3199,7 +3199,7 @@ gfxFont* gfxFontGroup::WhichPrefFontSupportsChar(uint32_t aCh,
         return mLastPrefFont;
       }
 
-      gfxFontEntry* fe = family->FindFontForStyle(mStyle);
+      gfxFontEntry* fe = family.mUnshared->FindFontForStyle(mStyle);
       if (!fe) {
         continue;
       }
@@ -3219,7 +3219,7 @@ gfxFont* gfxFontGroup::WhichPrefFontSupportsChar(uint32_t aCh,
 
       // If the char was not available, see if we can fall back to an
       // alternative face in the same family.
-      gfxFont* prefFont = FindFallbackFaceForChar(family, aCh);
+      gfxFont* prefFont = FindFallbackFaceForChar(family.mUnshared, aCh);
       if (prefFont) {
         mLastPrefFamily = family;
         mLastPrefFont = prefFont;

gfx/thebes/gfxTextRun.h

@@ -1186,7 +1186,7 @@ class gfxFontGroup final : public gfxTextRunFactory {
   RefPtr<gfxTextRun> mCachedEllipsisTextRun;
 
   // cache the most recent pref font to avoid general pref font lookup
-  RefPtr<gfxFontFamily> mLastPrefFamily;
+  FontFamily mLastPrefFamily;
   RefPtr<gfxFont> mLastPrefFont;
   eFontPrefLang mLastPrefLang;  // lang group for last pref font
   eFontPrefLang mPageLang;