Switch ChromeOS Chromium login to use IJG libjpeg

build/common.gypi

 # Copyright (c) 2012 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 894 matching lines @@
         #
         # On Aura, this allows per-tile painting to be used in the browser
         # compositor.
         ['OS!="android" and OS!="ios"', {
           'use_canvas_skia%': 1,
         }],
 
         ['chromeos==1', {
           'enable_basic_printing%': 0,
           'enable_print_preview%': 1,
-          # When building for ChromeOS we dont want Chromium to use libjpeg_turbo.
-          'use_libjpeg_turbo%': 0,
         }],
 
         # Do not enable the Settings App on ChromeOS.
         ['enable_app_list==1 and chromeos==0', {
           'enable_settings_app%': 1,
         }, {
           'enable_settings_app%': 0,
         }],
 
         ['OS=="linux" and target_arch=="arm" and chromeos==0', {
@@ skipping 568 matching lines @@
     'ozone_platform_dri%': 0,
     'ozone_platform_drm%': 0,
     'ozone_platform_egltest%': 0,
     'ozone_platform_gbm%': 0,
     'ozone_platform_ozonex%': 0,
     'ozone_platform_test%': 0,
 
     # Experiment: http://crbug.com/426914
     'envoy%': 0,
 
+    # Used to set libjpeg_gyp_path. Chrome OS ui/gfx/gfx.gyp uses the IJG path
+    # for robust login screen decoding.
+    'libjpeg_ijg_gyp_path': '../third_party/libjpeg/libjpeg.gyp',

[Nico, 2015/05/05 18:05:42]

I think you need to say <(DEPTH) instead of .. in gypi files, so that this works
in all targets, not just targets one up

[Ed Baker, 2015/05/05 22:03:34]

Done.

+    'libjpeg_turbo_gyp_path': '../third_party/libjpeg_turbo/libjpeg.gyp',
+
     'conditions': [
       ['buildtype=="Official"', {
         # Continue to embed build meta data in Official builds, basically the
         # time it was built.
         # TODO(maruel): This decision should be revisited because having an
         # official deterministic build has high value too but MSVC toolset can't
         # generate anything deterministic with WPO enabled AFAIK.
         'dont_embed_build_metadata%': 0,
       }],
       # Enable the Syzygy optimization step for the official builds.
@@ skipping 463 matching lines @@
       ['target_arch=="arm" or target_arch=="mipsel" or target_arch=="mips64el"', {
         'disable_glibc%': 1,
       }, {
         'disable_glibc%': 0,
       }],
 
       # Set the relative path from this file to the GYP file of the JPEG
       # library used by Chromium.
       ['use_system_libjpeg==1 or use_libjpeg_turbo==0', {
         # Configuration for using the system libjeg is here.
-        'libjpeg_gyp_path': '../third_party/libjpeg/libjpeg.gyp',
+        'libjpeg_gyp_path': '<(libjpeg_ijg_gyp_path)',
       }, {
-        'libjpeg_gyp_path': '../third_party/libjpeg_turbo/libjpeg.gyp',
+        'libjpeg_gyp_path': '<(libjpeg_turbo_gyp_path)',
       }],
 
       # Options controlling the use of GConf (the classic GNOME configuration
       # system) and GIO, which contains GSettings (the new GNOME config system).
       ['chromeos==1 or embedded==1', {
         'use_gconf%': 0,
         'use_gio%': 0,
       }, {
         'use_gconf%': 1,
         'use_gio%': 1,
@@ skipping 4134 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }