Revert of Resurrect Aura Linux accessibility. (patchset #15 id:280001 of https://codereview.chromium.org/975113002/)

Reason for revert:
Caused compile failure on Linux x64 bot (http://build.chromium.org/p/chromium.chrome/builders/Google%20Chrome%20Linux%20x64/builds/56532)

Output snippet:
FAILED: cd ../../chrome; flock -- /tmp/linux_package_lock bash ../out/Release/installer/debian/build.sh -o../out/Release -b ../out/Release -a x64 -c unstable
dpkg-shlibdeps: warning: binaries to analyze should already be installed in their package's directory.
2a3
> libatk1.0-0 (>= 1.12.4)

ERROR: Shared library dependencies changed!
If this is intentional, please update:
chrome/installer/linux/debian/expected_deps_ia32
chrome/installer/linux/debian/expected_deps_x64

Original issue's description:
> Resurrect Aura Linux accessibility.
>
> This is based in part on the ATK code we had as part of the Linux GTK port
> that went away, but now rewritten on top of AXPlatformNode. This patch
> successfully exposes an accessibility tree for Views and exposes top-level
> windows and the the role and name of each View. You can test it using
> accerciser. This is just to get the infrastructure in place - we need to
> implement more of the interface for it to be useful for accessibility tools.
>
> BUG=463671
>
> Committed: https://crrev.com/f65bad877350b5f7857d29e4b1b0d4d3f5c7cb6d
> Cr-Commit-Position: refs/heads/master@{#320383}

TBR=plundblad@chromium.org,dpranke@chromium.org,sky@chromium.org,gunsch@chromium.org,dmazzoni@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=463671

Review URL: https://codereview.chromium.org/1002993002

Cr-Original-Commit-Position: refs/heads/master@{#320402}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 999e4c26444e68898d4fa642783263b6e408b7e3

config/linux/BUILD.gn

@@ -35,25 +35,6 @@ config("sdk") {
   }
 }
 
-pkg_config("atk") {
-  packages = [ "atk" ]
-  atk_lib_dir = exec_script(pkg_config_script,
-                            [
-                              "--libdir",
-                              "atk",
-                            ],
-                            "string")
-  defines = [ "ATK_LIB_DIR=\"$atk_lib_dir\"" ]
-}
-
-# gn orders flags on a target before flags from configs. The default config
-# adds -Wall, and these flags have to be after -Wall -- so they need to come
-# from a config and can't be on the target directly.
-config("atk_warnings") {
-  # glib uses the pre-c++11 typedef-as-static_assert hack.
-  cflags = [ "-Wno-unused-local-typedef" ]
-}
-
 config("fontconfig") {
   libs = [ "fontconfig" ]
 }

config/linux/pkg-config.py

@@ -112,7 +112,6 @@ parser.add_option('-s', action='store', dest='sysroot', type='string')
 parser.add_option('-a', action='store', dest='arch', type='string')
 parser.add_option('--atleast-version', action='store',
                   dest='atleast_version', type='string')
-parser.add_option('--libdir', action='store_true', dest='libdir')
 (options, args) = parser.parse_args()
 
 # Make a list of regular expressions to strip out.
@@ -139,18 +138,6 @@ if options.atleast_version:
     print "false"
   sys.exit(0)
 
-if options.libdir:
-  try:
-    libdir = subprocess.check_output([options.pkg_config,
-                                      "--variable=libdir"] +
-                                     args,
-                                     env=os.environ)
-  except:
-    print "Error from pkg-config."
-    sys.exit(1)
-  sys.stdout.write(libdir.strip())
-  sys.exit(0)
-
 try:
   flag_string = subprocess.check_output(
       [ options.pkg_config, "--cflags", "--libs-only-l", "--libs-only-L" ] +

linux/system.gyp

@@ -90,30 +90,6 @@
       # Hide GTK and related dependencies for Chrome OS and Ozone, so they won't get
       # added back to Chrome OS and Ozone. Don't try to use GTK on Chrome OS and Ozone.
       'targets': [
-        {
-          'target_name': 'atk',
-          'type': 'none',
-          'conditions': [
-            ['_toolset=="target"', {
-              'direct_dependent_settings': {
-                'cflags': [
-                  '<!@(<(pkg-config) --cflags atk)',
-                ],
-                'defines': [
-                  'ATK_LIB_DIR="<!@(<(pkg-config) --variable=libdir atk)"',
-                ],
-              },
-              'link_settings': {
-                'ldflags': [
-                  '<!@(<(pkg-config) --libs-only-L --libs-only-other atk)',
-                ],
-                'libraries': [
-                  '<!@(<(pkg-config) --libs-only-l atk)',
-                ],
-              },
-            }],
-          ],
-        },
         {
           'target_name': 'gdk',
           'type': 'none',