Add -lrt flag to enable the usage of clock_gettime. Enable RawCodec for ChromeOS

gyp/common_variables.gypi

 # Copyright 2012 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.
 
 {
   # Get ready for the ugly...
   #
   # - We have to nest our variables dictionaries multiple levels deep, so that
   #   this and other gyp files can rely on previously-set variable values in
@@ skipping 43 matching lines @@
         'vulkan_merged_into_skia': '1',
         'skia_android_framework%': 0,
         'conditions' : [
           [ 'skia_os in ["linux", "freebsd", "openbsd", "solaris", "mac"]', {
             'skia_arch_type%': 'x86_64',
           }, {
             'skia_arch_type%': 'x86',
           }],
           # RAW codec needs exceptions. Due to that, it is a separate target. Its usage can be
           # controlled by skia_codec_decodes_raw.
-          ['skia_os == "chromeos" or skia_os == "win"', {
-            # FIXME: fix the support for ChromeOS [DNG SDK issue with clock_gettime()].
+          ['skia_os == "win"', {
             'skia_codec_decodes_raw%' : 0,
           }, {
             'skia_codec_decodes_raw%' : 1,
           }],
         ],
         'arm_version%': 0,
         'arm_neon%': 0,
         'skia_egl%': 0,
       },
 
@@ skipping 184 matching lines @@
         #'-ffast-math',           # Optimize float math even when it breaks IEEE compliance.
         #'-flto'                  # Enable link-time optimization.
     ],
 
     # These are referenced by our .gypi files that list files (e.g. core.gypi)
     #
     'skia_src_path%': '../src',
     'skia_include_path%': '../include',
   },
 }