We don't flatten or unflatten SkPaintOptionsAndroid. Reproduce and fix.

tests/AndroidPaintTest.cpp

+#ifdef SK_BUILD_FOR_ANDROID
+
+#include "SkPaintOptionsAndroid.h"
+#include "SkOrderedReadBuffer.h"
+#include "SkOrderedWriteBuffer.h"
+#include "SkPaint.h"
+#include "Test.h"
+#include "TestClassDef.h"
+
+static bool Equal(const SkPaintOptionsAndroid& a, const SkPaintOptionsAndroid& b) {
+    return !(a != b);
+}
+
+static void android_cjk_serialization(skiatest::Reporter* r) {
+    // We want to make sure that Android's paint options survive a flatten/unflatten round trip.
+    // These are all non-default options.
+    SkPaintOptionsAndroid options;
+    options.setLanguage("ja-JP");
+    options.setFontVariant(SkPaintOptionsAndroid::kElegant_Variant);
+    options.setUseFontFallbacks(true);
+
+    SkPaint paint;
+    paint.setPaintOptionsAndroid(options);
+
+    // Flatten the paint.
+    SkOrderedWriteBuffer writer(64 /*arbitrary*/);
+    paint.flatten(writer);
+    const size_t size = writer.bytesWritten();
+    SkAutoMalloc bytes(size);
+    writer.writeToMemory(bytes.get());
+
+    // Unflatten the bytes into a new paint.
+    SkPaint reconstructed;
+    SkOrderedReadBuffer reader(bytes.get(), size);
+    reconstructed.unflatten(reader);
+
+    REPORTER_ASSERT(r, Equal(options, reconstructed.getPaintOptionsAndroid()));
+}
+DEFINE_TESTCLASS_SHORT(android_cjk_serialization);
+
+#endif  // SK_BUILD_FOR_ANDROID