Decouple contrast boost from fake gamma.

src/ports/SkFontHost_mac.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 "SkTypes.h"  // Keep this before any #ifdef ...
 #if defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)
 
@@ skipping 2012 matching lines @@
     // Fonts may mix outlines and bitmaps, so information is needed on a glyph by glyph basis.
     // If a font contains an 'sbix' table, consider it to be a color font, and disable lcd.
     if (fHasColorGlyphs) {
         rec->fMaskFormat = SkMask::kARGB32_Format;
     }
 
     // Unhinted A8 masks (those not derived from LCD masks) must respect SK_GAMMA_APPLY_TO_A8.
     // All other masks can use regular gamma.
     if (SkMask::kA8_Format == rec->fMaskFormat && SkPaint::kNo_Hinting == hinting) {
 #ifndef SK_GAMMA_APPLY_TO_A8
+        // SRGBTODO: Is this correct? Do we want contrast boost?
         rec->ignorePreBlend();
 #endif
     } else {
         //CoreGraphics dialates smoothed text as needed.
         rec->setContrast(0);
     }
 }
 
 // we take ownership of the ref
 static const char* get_str(CFStringRef ref, SkString* str) {
@@ skipping 581 matching lines @@
         }
         return face;
     }
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SkFontMgr* SkFontMgr::Factory() { return new SkFontMgr_Mac; }
 
 #endif//defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)