Re-land: Resurrect Aura Linux accessibility.

build/linux/system.gyp

Index: build/linux/system.gyp
diff --git a/build/linux/system.gyp b/build/linux/system.gyp
index a71a5c5927fa5d2bb777a8ec68f4a1b5f61858e6..ed7f942fd68b8b578d2a514883da97d9844af0d2 100644
--- a/build/linux/system.gyp
+++ b/build/linux/system.gyp
@@ -91,6 +91,30 @@
       # 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',
           'conditions': [