Decouple contrast boost from fake gamma.

src/ports/SkFontHost_FreeType.cpp

Index: src/ports/SkFontHost_FreeType.cpp
diff --git a/src/ports/SkFontHost_FreeType.cpp b/src/ports/SkFontHost_FreeType.cpp
index 5c00d1b697194c33edb02cf9d2d6688ecc6bf9a2..2a398fef2df9b967283e5c06d043b0addd82cb58 100644
--- a/src/ports/SkFontHost_FreeType.cpp
+++ b/src/ports/SkFontHost_FreeType.cpp
@@ -714,7 +714,8 @@ void SkTypeface_FreeType::onFilterRec(SkScalerContextRec* rec) const {
 
 #ifndef SK_GAMMA_APPLY_TO_A8
     if (!isLCD(*rec)) {
-      rec->ignorePreBlend();
+        // SRGBTODO: Is this correct?

[bungeman-skia, 2016/04/07 20:15:45]

Yeah... so by default we don't apply the gamma stuff to A8, but that means we
also don't apply the contrast. The idea being that if you didn't ask for gamma
you were going to do the linear blit anyway, and that linear blit would provide
the 'contrast' (at least for the common case of black on white). I don't know
what the right thing is here either.

+        rec->ignorePreBlend(false);
     }
 #endif
 }