skia: Use discardable memory for scaled image cache.

skia/skia_common.gypi

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This gypi file handles the removal of platform-specific files from the
 # Skia build.
 {
   'include_dirs': [
     '..',
     'config',
@@ skipping 173 matching lines @@
     'IGNORE_ROT_AA_RECT_OPT',
 
     'SK_IGNORE_BLURRED_RRECT_OPT',
 
     'SK_IGNORE_QUAD_RR_CORNERS_OPT',
 
     # this flag forces Skia not to use typographic metrics with GDI.
     'SK_GDI_ALWAYS_USE_TEXTMETRICS_FOR_FONT_METRICS',
 
     'SK_DEFAULT_FONT_CACHE_LIMIT=<(default_font_cache_limit)',
+
+    'SK_USE_DISCARDABLE_SCALEDIMAGECACHE',
   ],
 
   'direct_dependent_settings': {
     'defines': [
       '<@(skia_export_defines)',
     ],
   },
 
   # We would prefer this to be direct_dependent_settings,
   # however we currently have no means to enforce that direct dependents
   # re-export if they include Skia headers in their public headers.
   'all_dependent_settings': {
     'include_dirs': [
       '..',
       'config',
     ],
   },
 
   'msvs_disabled_warnings': [4244, 4267, 4341, 4345, 4390, 4554, 4748, 4800],
 }