Use the font typeface when available instead of rematch

The font fallback is returning a specific typeface. The
specific typeface should be used when available to avoid
a font family match (which may leads to a different font
being used).

As an example, on Fuchsia the script Bengali is using the
'Mukti Narrow' which is not getting match correctly. That
makes the script being broken. We are not seeing a
regression since the expensive fallbacks algorithm is
catching the broken cases.

see:
  https://chromium-review.googlesource.com/c/chromium/src/+/1824104
  http://crbug.com/1003829

Bug: 1008407, 1018321
Change-Id: I668382707e24ecc267a82531ad2a77c23283b2b3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1884657Reviewed-by: Robert Liao <robliao@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Commit-Queue: Etienne Bergeron <etienneb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710065}

ui/gfx/font.h

@@ -124,11 +124,8 @@ class GFX_EXPORT Font {
   NativeFont GetNativeFont() const;
 #endif
 
-#if defined(OS_WIN)
-  // Raw access to the underlying platform font implementation. Can be
-  // static_cast to a known implementation type if needed.
+  // Raw access to the underlying platform font implementation.
   PlatformFont* platform_font() const { return platform_font_.get(); }
-#endif
 
  private:
   // Wrapped platform font implementation.

ui/gfx/font_fallback_win_unittest.cc

@@ -18,6 +18,7 @@
 #include "third_party/icu/source/common/unicode/uscript.h"
 #include "third_party/icu/source/common/unicode/utf16.h"
 #include "third_party/skia/include/core/SkTypeface.h"
+#include "ui/gfx/platform_font.h"
 #include "ui/gfx/test/font_fallback_test_data.h"
 
 #if defined(OS_WIN)
@@ -105,7 +106,12 @@ class GetFallbackFontTest
 
   bool DoesFontSupportCodePoints(Font font, const base::string16& text) {
     sk_sp<SkTypeface> skia_face =
-        SkTypeface::MakeFromName(font.GetFontName().c_str(), SkFontStyle());
+        font.platform_font()->GetNativeSkTypefaceIfAvailable();
+    if (!skia_face) {
+      // Performs a family match when the typeface is not available.
+      skia_face =
+          SkTypeface::MakeFromName(font.GetFontName().c_str(), SkFontStyle());
+    }
 
     size_t i = 0;
     const SkGlyphID kUnsupportedGlyph = 0;

ui/gfx/render_text_harfbuzz.cc

@@ -40,6 +40,7 @@
 #include "ui/gfx/font_render_params.h"
 #include "ui/gfx/geometry/safe_integer_conversions.h"
 #include "ui/gfx/harfbuzz_font_skia.h"
+#include "ui/gfx/platform_font.h"
 #include "ui/gfx/range/range_f.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gfx/switches.h"
@@ -54,10 +55,6 @@
 #include "base/android/locale_utils.h"
 #endif  // defined(OS_ANDROID)
 
-#if defined(OS_WIN)
-#include "ui/gfx/platform_font.h"
-#endif
-
 #include <hb.h>
 
 namespace gfx {
@@ -828,15 +825,9 @@ bool TextRunHarfBuzz::FontParams::SetRenderParamsRematchFont(
 bool TextRunHarfBuzz::FontParams::SetRenderParamsOverrideSkiaFaceFromFont(
     const Font& fallback_font,
     const FontRenderParams& new_render_params) {
-  sk_sp<SkTypeface> new_skia_face;
-#if defined(OS_WIN)
-  // TODO(https://crbug.com/1008407): Extend this to additional platforms that
-  // use PlatformFontSkia.
   PlatformFont* platform_font = fallback_font.platform_font();
-  if (platform_font) {
-    new_skia_face = platform_font->GetNativeSkTypefaceIfAvailable();
-  }
-#endif
+  sk_sp<SkTypeface> new_skia_face =
+      platform_font->GetNativeSkTypefaceIfAvailable();
 
   // If pass-through of the Skia native handle fails for PlatformFonts other
   // than PlatformFontSkia, perform rematching.