Use Skia's matchFamilyStyleCharacter API for font fallback

content/child/font_warmup_win.cc

Index: content/child/font_warmup_win.cc
diff --git a/content/child/font_warmup_win.cc b/content/child/font_warmup_win.cc
index 33d18075f642e518a148ade4e5808f83d791a259..bae981c296f35ae907218daa91f7f3eda8126a31 100644
--- a/content/child/font_warmup_win.cc
+++ b/content/child/font_warmup_win.cc
@@ -5,6 +5,7 @@
 #include "content/child/font_warmup_win.h"
 
 #include <dwrite.h>
+#include <dwrite_2.h>
 #include <stdint.h>
 #include <map>
 
@@ -21,6 +22,7 @@
 #include "base/sys_byteorder.h"
 #include "base/trace_event/trace_event.h"
 #include "base/win/iat_patch_function.h"
+#include "base/win/scoped_comptr.h"
 #include "base/win/windows_version.h"
 #include "content/public/common/dwrite_font_platform_win.h"
 #include "ppapi/shared_impl/proxy_lock.h"
@@ -458,8 +460,16 @@ SkFontMgr* GetPreSandboxWarmupFontMgr() {
     IDWriteFactory* factory;
     CreateDirectWriteFactory(&factory);
 
-    g_warmup_fontmgr =
-        SkFontMgr_New_DirectWrite(factory, GetCustomFontCollection(factory));
+    // DirectWrite font fallback does not work if it is initialized after the
+    // sandbox starts.
+    base::win::ScopedComPtr<IDWriteFactory2> factory2;
+    factory->QueryInterface<IDWriteFactory2>(factory2.Receive());
+    base::win::ScopedComPtr<IDWriteFontFallback> font_fallback;
+    if (factory2.get())
+      factory2->GetSystemFontFallback(font_fallback.Receive());
+
+    g_warmup_fontmgr = SkFontMgr_New_DirectWrite(
+        factory, GetCustomFontCollection(factory), font_fallback.get());
     blink::WebFontRendering::setSkiaFontManager(g_warmup_fontmgr);
   }
   return g_warmup_fontmgr;