Add gamepad data fetcher for Linux

content/content_browser.gypi

Index: content/content_browser.gypi
diff --git a/content/content_browser.gypi b/content/content_browser.gypi
index 69db33ad33f7f93c68c4cee6f65ad4e8f353dd74..1a5089c9577a487168cc74c795c9419332cefa57 100644
--- a/content/content_browser.gypi
+++ b/content/content_browser.gypi
@@ -232,14 +232,19 @@
     'browser/font_list_async.cc',
     'browser/font_list_async.h',
     'browser/gamepad/data_fetcher.h',
-    'browser/gamepad/data_fetcher_mac.mm',
-    'browser/gamepad/data_fetcher_mac.h',
-    'browser/gamepad/data_fetcher_win.cc',
-    'browser/gamepad/data_fetcher_win.h',
     'browser/gamepad/gamepad_provider.cc',
     'browser/gamepad/gamepad_provider.h',
     'browser/gamepad/gamepad_service.cc',
     'browser/gamepad/gamepad_service.h',
+    'browser/gamepad/gamepad_standard_mappings_linux.cc',
+    'browser/gamepad/gamepad_standard_mappings_linux.h',
+    'browser/gamepad/platform_data_fetcher.h',
+    'browser/gamepad/platform_data_fetcher_linux.cc',
+    'browser/gamepad/platform_data_fetcher_linux.h',
+    'browser/gamepad/platform_data_fetcher_mac.h',
+    'browser/gamepad/platform_data_fetcher_mac.mm',
+    'browser/gamepad/platform_data_fetcher_win.cc',
+    'browser/gamepad/platform_data_fetcher_win.h',
     'browser/geolocation/arbitrator_dependency_factory.cc',
     'browser/geolocation/arbitrator_dependency_factory.h',
     'browser/geolocation/core_location_data_provider_mac.h',
@@ -706,6 +711,11 @@
         }],
       ],
     }],
+    ['OS=="linux"', {
+      'dependencies': [
+        '../build/linux/system.gyp:udev',
+      ],
+    }],
     ['OS=="linux" and toolkit_uses_gtk==0', {
       'dependencies': [
         '../build/linux/system.gyp:dbus',