Add gamepad data fetcher for Linux

build/linux/system.gyp

Index: build/linux/system.gyp
diff --git a/build/linux/system.gyp b/build/linux/system.gyp
index a2b57cc587b2876d50fd5a429b5979983eeb8e39..32d2935aee0031f7aa0d7904d7094ae7760c6e81 100644
--- a/build/linux/system.gyp
+++ b/build/linux/system.gyp
@@ -625,5 +625,26 @@
         }],
       ],
     },
+    {
+      'target_name': 'udev',
+      'type': 'none',
+      'conditions': [
+        ['_toolset=="target"', {
+          'direct_dependent_settings': {
+            'cflags': [
+              '<!@(<(pkg-config) --cflags libudev)'
+            ],
+          },
+          'link_settings': {
+            'ldflags': [
+              '<!@(<(pkg-config) --libs-only-L --libs-only-other libudev)',
+            ],
+            'libraries': [
+              '<!@(<(pkg-config) --libs-only-l libudev)',
+            ],
+          },
+        }],
+      ],
+    },
   ],
 }