Add a gyp target for Xext to linux/system so that Views can depend on it. A recent change added a code dependency within Views on linux on this library. Chrome was linking with it but other Views apps (candidate_window) weren't

Review URL: http://codereview.chromium.org/758002

git-svn-id: http://src.chromium.org/svn/trunk/src/build@41097 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

linux/system.gyp

@@ -222,6 +222,26 @@
           },
       }]]
     },
+    {
+      'target_name': 'xext',
+      'type': 'settings',
+      'conditions': [
+        ['_toolset=="target"', {
+          'direct_dependent_settings': {
+            'cflags': [
+              '<!@(<(pkg-config) --cflags xext)',
+            ],
+          },
+          'link_settings': {
+            'ldflags': [
+              '<!@(<(pkg-config) --libs-only-L --libs-only-other xext)',
+            ],
+            'libraries': [
+              '<!@(<(pkg-config) --libs-only-l xext)',
+            ],
+          },
+      }]]
+    },
     {
       'target_name': 'selinux',
       'type': 'settings',