Revert of Gamma correction for distance field text.

include/core/SkPaint.h

Index: include/core/SkPaint.h
diff --git a/include/core/SkPaint.h b/include/core/SkPaint.h
index f766ca1c7f35c259d3f4b28a6f0dbc3f782b499d..95fc0b87ad0be45dc85cd0569849c24e766d50d6 100644
--- a/include/core/SkPaint.h
+++ b/include/core/SkPaint.h
@@ -1081,8 +1081,7 @@
     SkScalar measure_text(SkGlyphCache*, const char* text, size_t length,
                           int* count, SkRect* bounds) const;
 
-    SkGlyphCache* detachCache(const SkDeviceProperties* deviceProperties, const SkMatrix*,
-                              bool ignoreGamma) const;
+    SkGlyphCache* detachCache(const SkDeviceProperties* deviceProperties, const SkMatrix*) const;
 
     void descriptorProc(const SkDeviceProperties* deviceProperties, const SkMatrix* deviceMatrix,
                         void (*proc)(SkTypeface*, const SkDescriptor*, void*),
@@ -1132,7 +1131,6 @@
     }
 
     friend class SkAutoGlyphCache;
-    friend class SkAutoGlyphCacheNoGamma;
     friend class SkCanvas;
     friend class SkDraw;
     friend class SkGraphics; // So Term() can be called.