Remove DEFINE_FONT_DATA_TYPE_CASTS and use new downcast helper

This CL has two goals,
  1. Remove DEFINE_FONT_DATA_TYPE_CASTS.
  2. Use new downast helpers for blink::SegmentedFontData and
     blink::SimpleFontData.

Bug: 891908
Change-Id: Ia42e0f889a11462545463c205a324152900d7ea6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2019749Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Abhijeet Kandalkar <abhijeet@igalia.com>
Cr-Commit-Position: refs/heads/master@{#751253}

third_party/blink/renderer/platform/fonts/font_data.h

@@ -57,15 +57,6 @@ class PLATFORM_EXPORT FontData : public RefCounted<FontData> {
   DISALLOW_COPY_AND_ASSIGN(FontData);
 };
 
-#define DEFINE_FONT_DATA_TYPE_CASTS(thisType, predicate)     \
-  template <typename T>                                      \
-  inline thisType* To##thisType(const scoped_refptr<T>& fontData) { \
-    return To##thisType(fontData.get());                     \
-  }                                                          \
-  DEFINE_TYPE_CASTS(thisType, FontData, fontData,            \
-                    fontData->IsSegmented() == predicate,    \
-                    fontData.IsSegmented() == predicate)
-
 }  // namespace blink
 
 #endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_FONT_DATA_H_

third_party/blink/renderer/platform/fonts/font_fallback_iterator.cc

@@ -153,7 +153,7 @@ scoped_refptr<FontDataForRangeSet> FontFallbackIterator::Next(
     current_font_data_index_++;
     if (!font_data->IsLoading()) {
       scoped_refptr<SimpleFontData> non_segmented =
-          const_cast<SimpleFontData*>(ToSimpleFontData(font_data));
+          const_cast<SimpleFontData*>(To<SimpleFontData>(font_data));
       // The fontData object that we have here is tracked in m_fontList of
       // FontFallbackList and gets released in the font cache when the
       // FontFallbackList is destroyed.
@@ -165,7 +165,7 @@ scoped_refptr<FontDataForRangeSet> FontFallbackIterator::Next(
 
   // Iterate over ranges of a segmented font below.
 
-  const SegmentedFontData* segmented = ToSegmentedFontData(font_data);
+  const auto* segmented = To<SegmentedFontData>(font_data);
   if (fallback_stage_ != kSegmentedFace) {
     segmented_face_index_ = 0;
     fallback_stage_ = kSegmentedFace;

third_party/blink/renderer/platform/fonts/font_fallback_list.cc

@@ -69,7 +69,7 @@ void FontFallbackList::ReleaseFontData() {
     if (!font_list_[i]->IsCustomFont()) {
       DCHECK(!font_list_[i]->IsSegmented());
       FontCache::GetFontCache()->ReleaseFontData(
-          ToSimpleFontData(font_list_[i]));
+          To<SimpleFontData>(font_list_[i].get()));
     }
   }
   shape_cache_.reset();  // Clear the weak pointer to the cache instance.
@@ -125,8 +125,8 @@ const SimpleFontData* FontFallbackList::DeterminePrimarySimpleFontData(
       return last_resort_fallback;
     }
 
-    if (font_data->IsSegmented() &&
-        !ToSegmentedFontData(font_data)->ContainsCharacter(kSpaceCharacter))
+    const auto* segmented = DynamicTo<SegmentedFontData>(font_data);
+    if (segmented && !segmented->ContainsCharacter(kSpaceCharacter))
       continue;
 
     const SimpleFontData* font_data_for_space =
@@ -139,8 +139,7 @@ const SimpleFontData* FontFallbackList::DeterminePrimarySimpleFontData(
     if (!font_data_for_space->IsLoadingFallback())
       return font_data_for_space;
 
-    if (font_data->IsSegmented()) {
-      const SegmentedFontData* segmented = ToSegmentedFontData(font_data);
+    if (segmented) {
       for (unsigned i = 0; i < segmented->NumFaces(); i++) {
         const SimpleFontData* range_font_data =
             segmented->FaceAt(i)->FontData();
@@ -223,8 +222,9 @@ FallbackListCompositeKey FontFallbackList::CompositeKey(
       if (result) {
         bool is_unique_match = false;
         key.Add(font_description.CacheKey(params, is_unique_match));
-        if (!result->IsSegmented() && !result->IsCustomFont())
-          FontCache::GetFontCache()->ReleaseFontData(ToSimpleFontData(result));
+        auto* font_data = DynamicTo<SimpleFontData>(result.get());
+        if (!font_data && !result->IsCustomFont())
+          FontCache::GetFontCache()->ReleaseFontData(font_data);
       }
     }
     current_family = current_family->Next();

third_party/blink/renderer/platform/fonts/segmented_font_data.h

@@ -29,6 +29,7 @@
 #include "third_party/blink/renderer/platform/fonts/font_data.h"
 #include "third_party/blink/renderer/platform/fonts/font_data_for_range_set.h"
 #include "third_party/blink/renderer/platform/platform_export.h"
+#include "third_party/blink/renderer/platform/wtf/casting.h"
 
 class SimpleFontData;
 
@@ -61,7 +62,12 @@ class PLATFORM_EXPORT SegmentedFontData : public FontData {
   Vector<scoped_refptr<FontDataForRangeSet>, 1> faces_;
 };
 
-DEFINE_FONT_DATA_TYPE_CASTS(SegmentedFontData, true);
+template <>
+struct DowncastTraits<SegmentedFontData> {
+  static bool AllowFrom(const FontData& fontData) {
+    return fontData.IsSegmented();
+  }
+};
 
 }  // namespace blink
 

third_party/blink/renderer/platform/fonts/simple_font_data.h

@@ -39,6 +39,7 @@
 #include "third_party/blink/renderer/platform/fonts/typesetting_features.h"
 #include "third_party/blink/renderer/platform/geometry/float_rect.h"
 #include "third_party/blink/renderer/platform/platform_export.h"
+#include "third_party/blink/renderer/platform/wtf/casting.h"
 #include "third_party/blink/renderer/platform/wtf/text/string_hash.h"
 #include "third_party/skia/include/core/SkFont.h"
 
@@ -245,7 +246,12 @@ ALWAYS_INLINE float SimpleFontData::WidthForGlyph(Glyph glyph) const {
 #endif
 }
 
-DEFINE_FONT_DATA_TYPE_CASTS(SimpleFontData, false);
+template <>
+struct DowncastTraits<SimpleFontData> {
+  static bool AllowFrom(const FontData& fontData) {
+    return !fontData.IsSegmented();
+  }
+};
 
 }  // namespace blink
 #endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SIMPLE_FONT_DATA_H_