Disable SK_GAMMA_SRGB on android builds.

gyp/common_conditions.gypi

 # conditions used in both common.gypi and skia.gyp in chromium
 #
 {
   'defines': [
     'SK_ALLOW_STATIC_GLOBAL_INITIALIZERS=<(skia_static_initializers)',
     'SK_SUPPORT_GPU=<(skia_gpu)',
     'SK_SUPPORT_OPENCL=<(skia_opencl)',
     'SK_FORCE_DISTANCEFIELD_FONTS=<(skia_force_distancefield_fonts)',
   ],
   'conditions' : [
@@ skipping 534 matching lines @@
           'GCC_THUMB_SUPPORT': 'NO',
         },
       },
     ],
 
     [ 'skia_os == "android"',
       {
         'defines': [
           'SK_BUILD_FOR_ANDROID',
           'SK_FONTHOST_DOES_NOT_USE_FONTMGR',
+
+          # Android Text Tuning
+          'SK_GAMMA_EXPONENT=1.4',
+          'SK_GAMMA_CONTRAST=0.0',
+        ],
+        # Android defines a fixed gamma exponent instead of using SRGB
+        'defines!': [
+          'SK_GAMMA_SRGB',
         ],
         'configurations': {
           'Debug': {
             'cflags': ['-g']
           },
           'Release': {
             'cflags': ['-O2'],
             'defines': [ 'NDEBUG' ],
           },
         },
@@ skipping 37 matching lines @@
       'defines': [
         'SK_USE_POSIX_THREADS',
       ],
     }],
   ], # end 'conditions'
   # The Xcode SYMROOT must be at the root. See build/common.gypi in chromium for more details
   'xcode_settings': {
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }