Implement SkFontMgr_Custom::onCreateFromFontData.

src/ports/SkFontMgr_custom.cpp

Index: src/ports/SkFontMgr_custom.cpp
diff --git a/src/ports/SkFontMgr_custom.cpp b/src/ports/SkFontMgr_custom.cpp
index 200173d987a4cf5030fcab2c188d1e640834eb70..da91e7ffaa138d00dc0d9b3b742398cb4d4d1e49 100644
--- a/src/ports/SkFontMgr_custom.cpp
+++ b/src/ports/SkFontMgr_custom.cpp
@@ -291,6 +291,19 @@ protected:
         return new SkTypeface_Stream(std::move(data), style, isFixedPitch, false, name);
     }
 
+    SkTypeface* onCreateFromFontData(SkFontData* data) const override {
+        bool isFixedPitch;
+        SkFontStyle style;
+        SkString name;
+        if (!fScanner.scanFont(data->getStream(), data->getIndex(),
+                               &name, &style, &isFixedPitch, nullptr))
+        {
+            return nullptr;
+        }
+        std::unique_ptr<SkFontData> unique_data(data);

[bungeman-skia, 2016/06/10 18:32:11]

Since no one outside Skia is using this right now, the next CL is to update the
interface to just take std::unique_ptr<SkFontData>.

+        return new SkTypeface_Stream(unique_data, style, isFixedPitch, false, name);
+    }
+
     SkTypeface* onCreateFromFile(const char path[], int ttcIndex) const override {
         SkAutoTDelete<SkStreamAsset> stream(SkStream::NewFromFile(path));
         return stream.get() ? this->createFromStream(stream.release(), ttcIndex) : nullptr;