Simplify textToGlyphs

Change-Id: I9f2ae8e669ab3c22b66f9b10bd2650b5f5ab0bd4
Reviewed-on: https://skia-review.googlesource.com/125345
Reviewed-by: Herb Derby <herb@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
Auto-Submit: Herb Derby <herb@google.com>
diff --git a/include/core/SkPaint.h b/include/core/SkPaint.h
index a564824..8cc8733 100644
--- a/include/core/SkPaint.h
+++ b/include/core/SkPaint.h
@@ -1306,9 +1306,7 @@
         @param byteLength  length of character storage in bytes
         @return            number of glyphs represented by text of length byteLength
     */
-    int countText(const void* text, size_t byteLength) const {
-        return this->textToGlyphs(text, byteLength, nullptr);
-    }
+    int countText(const void* text, size_t byteLength) const;
 
     /** Returns the advance width of text if kVerticalText_Flag is clear,
         and the height of text if kVerticalText_Flag is set.