Reland of "Update linux sysroot from Wheezy to Jessie"

build/linux/sysroot_scripts/install-sysroot.py

Index: build/linux/sysroot_scripts/install-sysroot.py
diff --git a/build/linux/sysroot_scripts/install-sysroot.py b/build/linux/sysroot_scripts/install-sysroot.py
index d79c12bbbbcef46057e6be67da92b5654d528709..c8e88ee0a8ab2b4edf35ec6201e57caae8d9da65 100755
--- a/build/linux/sysroot_scripts/install-sysroot.py
+++ b/build/linux/sysroot_scripts/install-sysroot.py
@@ -6,16 +6,17 @@
 """Install Debian sysroots for building chromium.
 """
 
-# The sysroot is needed to ensure that binaries will run on Debian Wheezy,
-# the oldest supported linux distribution. For ARM64 linux, we have Debian
-# Jessie sysroot as Jessie is the first version with ARM64 support. This script
-# can be run manually but is more often run as part of gclient hooks. When run
-# from hooks this script is a no-op on non-linux platforms.
-
-# The sysroot image could be constructed from scratch based on the current
-# state or Debian Wheezy/Jessie but for consistency we currently use a
-# pre-built root image. The image will normally need to be rebuilt every time
-# chrome's build dependencies are changed.
+# The sysroot is needed to ensure that binaries that get built will run on
+# the oldest stable version of Debian that we currently support.
+# This script can be run manually but is more often run as part of gclient
+# hooks. When run from hooks this script is a no-op on non-linux platforms.
+
+# The sysroot image could be constructed from scratch based on the current state
+# of the Debian archive but for consistency we use a pre-built root image (we
+# don't want upstream changes to Debian to effect the chromium build until we
+# choose to pull them in). The images will normally need to be rebuilt every
+# time chrome's build dependencies are changed but should also be updated
+# periodically to include upstream security fixes from Debian.
 
 import hashlib
 import json
@@ -134,14 +135,6 @@
   if target_arch and target_arch not in (host_arch, 'i386'):
     InstallDefaultSysrootForArch(target_arch)
 
-  # Desktop Linux ozone builds require libxkbcommon* which is not
-  # available in Wheezy.
-  # TODO(thomasanderson): Remove this once the Jessie sysroot is used
-  # by default.
-  gyp_defines = gyp_chromium.GetGypVars(gyp_chromium.GetSupplementalFiles())
-  if gyp_defines.get('use_ozone') == '1':
-    InstallSysroot('Jessie', 'amd64')
-
 
 def main(args):
   parser = optparse.OptionParser('usage: %prog [OPTIONS]', description=__doc__)
@@ -150,6 +143,9 @@
                                         ' Installs default sysroot images.')
   parser.add_option('--arch', type='choice', choices=VALID_ARCHS,
                     help='Sysroot architecture: %s' % ', '.join(VALID_ARCHS))
+  parser.add_option('--all', action='store_true',
+                    help='Install all sysroot images (useful when updating the'
+                         ' images)')
   options, _ = parser.parse_args(args)
   if options.running_as_hook and not sys.platform.startswith('linux'):
     return 0
@@ -160,27 +156,23 @@
     if host_arch in ['ppc','s390']:
       return 0
     InstallDefaultSysroots(host_arch)
+  elif options.arch:
+    InstallDefaultSysrootForArch(options.arch)
+  elif options.all:
+    for arch in VALID_ARCHS:
+      InstallDefaultSysrootForArch(arch)
   else:
-    if not options.arch:
-      print 'You much specify either --arch or --running-as-hook'
-      return 1
-    InstallDefaultSysrootForArch(options.arch)
+    print 'You much specify either --arch, --all or --running-as-hook'
+    return 1
 
   return 0
 
+
 def InstallDefaultSysrootForArch(target_arch):
-  if target_arch == 'amd64':
-    InstallSysroot('Wheezy', 'amd64')
-  elif target_arch == 'arm':
-    InstallSysroot('Wheezy', 'arm')
-  elif target_arch == 'arm64':
-    InstallSysroot('Jessie', 'arm64')
-  elif target_arch == 'i386':
-    InstallSysroot('Wheezy', 'i386')
-  elif target_arch == 'mips':
-    InstallSysroot('Wheezy', 'mips')
-  else:
+  if target_arch not in VALID_ARCHS:
     raise Error('Unknown architecture: %s' % target_arch)
+  InstallSysroot('Jessie', target_arch)
+
 
 def InstallSysroot(target_platform, target_arch):
   # The sysroot directory should match the one specified in build/common.gypi.