Make SkFont a bit more useable

include/core/SkFont.h

Index: include/core/SkFont.h
diff --git a/include/core/SkFont.h b/include/core/SkFont.h
index 6c231c963a0fe6996c97511c0828edb82b9c2598..6e8a71501fec4315f164e82d247a44f6ed0f0f5a 100644
--- a/include/core/SkFont.h
+++ b/include/core/SkFont.h
@@ -126,6 +126,10 @@ public:
      *  If size is not supported (e.g. <= 0 or non-finite) NULL will be returned.
      */
     sk_sp<SkFont> makeWithSize(SkScalar size) const;
+    /**
+     *  Return a font with the same attributes of this font, but with the flags.
+     */
+    sk_sp<SkFont> makeWithFlags(uint32_t newFlags) const;
 
     SkTypeface* getTypeface() const { return fTypeface.get(); }
     SkScalar    getSize() const { return fSize; }
@@ -139,10 +143,15 @@ public:
     bool isEnableAutoHints() const { return SkToBool(fFlags & kEnableAutoHints_Flag); }
     bool isEnableByteCodeHints() const { return SkToBool(fFlags & kEnableByteCodeHints_Flag); }
     bool isUseNonLinearMetrics() const { return SkToBool(fFlags & kUseNonlinearMetrics_Flag); }
+    bool isDevKern() const { return SkToBool(fFlags & kDevKern_Flag); }
 
     int textToGlyphs(const void* text, size_t byteLength, SkTextEncoding,
                      uint16_t glyphs[], int maxGlyphCount) const;
 
+    int countText(const void* text, size_t byteLength, SkTextEncoding encoding) {
+        return this->textToGlyphs(text, byteLength, encoding, nullptr, 0);
+    }
+
     SkScalar measureText(const void* text, size_t byteLength, SkTextEncoding) const;
 
     static sk_sp<SkFont> Testing_CreateFromPaint(const SkPaint&);