x11: Split the gfx_x11 target into its own gyp file.

ui/gfx/gfx.gyp

Index: ui/gfx/gfx.gyp
diff --git a/ui/gfx/gfx.gyp b/ui/gfx/gfx.gyp
index f46a0c11ca7b75722af53665f559e61b91ca6304..2a4d72ca8fa412145116ec4710dbe0c730d1634f 100644
--- a/ui/gfx/gfx.gyp
+++ b/ui/gfx/gfx.gyp
@@ -380,7 +380,7 @@
         }],
         ['use_x11==1', {
           'dependencies': [
-            'gfx_x11',
+            'x/gfx_x11.gyp:gfx_x11',
           ],
         }],
         ['use_pango==1', {
@@ -565,31 +565,5 @@
         },
       ],
     }],
-    ['use_x11 == 1', {
-      'targets': [
-        {
-          'target_name': 'gfx_x11',
-          'type': '<(component)',
-          'dependencies': [
-            '../../base/base.gyp:base',
-            '../../build/linux/system.gyp:x11',
-            'gfx_geometry',
-          ],
-          'defines': [
-            'GFX_IMPLEMENTATION',
-          ],
-          'sources': [
-            'x/x11_atom_cache.cc',
-            'x/x11_atom_cache.h',
-            'x/x11_connection.cc',
-            'x/x11_connection.h',
-            'x/x11_error_tracker.cc',
-            'x/x11_error_tracker.h',
-            'x/x11_types.cc',
-            'x/x11_types.h',
-          ],
-        },
-      ]
-    }],
   ],
 }