Make SkBitmapCache remove invalid bitmaps from the SkResourceCache.

gyp/common.gypi

 # Copyright 2011 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.
 #
 # This file is automatically included by gyp_skia when building any target.
 
 {
   'includes': [
     'common_variables.gypi',
   ],
 
   'target_defaults': {
     'defines': [
       'SK_INTERNAL',
       'SK_GAMMA_SRGB',
       'SK_GAMMA_APPLY_TO_A8',
       'SK_SCALAR_TO_FLOAT_EXCLUDED',  # temporary to allow Chrome to call SkFloatToScalar
+      'SK_USE_DISCARDABLE_SCALEDIMAGECACHE',
     ],
 
     # Validate the 'skia_os' setting against 'OS', because only certain
     # combinations work.  You should only override 'skia_os' for certain
     # situations, like building for iOS on a Mac.
     'variables': {
       'conditions': [
         [ 'skia_os != OS and not ((skia_os == "ios" and OS == "mac") or \
                                   (skia_os == "nacl" and OS == "linux") or \
                                   (skia_os == "chromeos" and OS == "linux"))', {
@@ skipping 67 matching lines @@
           'Release': { 'defines': [ 'NDEBUG' ] },
           'Release_Developer': {
             'inherit_from': ['Release'],
             'defines': [ 'SK_DEVELOPER=1' ],
           },
         },
       }],
     ],
   }, # end 'target_defaults'
 }