Decouple contrast boost from fake gamma.

src/ports/SkFontHost_FreeType.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkAdvancedTypefaceMetrics.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 696 matching lines @@
     }
 
     // rotated text looks bad with hinting, so we disable it as needed
     if (!isAxisAligned(*rec)) {
         h = SkPaint::kNo_Hinting;
     }
     rec->setHinting(h);
 
 #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
 }
 
 int SkTypeface_FreeType::onGetUPEM() const {
     AutoFTAccess fta(this);
     FT_Face face = fta.face();
     return face ? face->units_per_EM : 0;
 }
 
@@ skipping 1086 matching lines @@
                 SkDEBUGF(("Requested font axis not found: %s '%c%c%c%c'\n",
                           name.c_str(),
                           (skTag >> 24) & 0xFF,
                           (skTag >> 16) & 0xFF,
                           (skTag >>  8) & 0xFF,
                           (skTag)       & 0xFF));
             }
         }
     )
 }