Rationalize linux vs x11 in ui

ui/gl/gl.gyp

Index: ui/gl/gl.gyp
diff --git a/ui/gl/gl.gyp b/ui/gl/gl.gyp
index b1527cb3c8bd0672331c414f68fec52b683929f8..3f2b35586cd81322bc1768f33dfab76ec362e0dc 100644
--- a/ui/gl/gl.gyp
+++ b/ui/gl/gl.gyp
@@ -66,13 +66,13 @@
         'gl_context.cc',
         'gl_context.h',
         'gl_context_android.cc',
-        'gl_context_linux.cc',
         'gl_context_mac.mm',
         'gl_context_osmesa.cc',
         'gl_context_osmesa.h',
         'gl_context_stub.cc',
         'gl_context_stub.h',
         'gl_context_win.cc',
+        'gl_context_x11.cc',
         'gl_export.h',
         'gl_fence.cc',
         'gl_fence.h',
@@ -81,17 +81,17 @@
         'gl_image.cc',
         'gl_image.h',
         'gl_image_android.cc',
-        'gl_image_linux.cc',
         'gl_image_mac.cc',
         'gl_image_stub.cc',
         'gl_image_stub.h',
         'gl_image_win.cc',
+        'gl_image_x11.cc',
         'gl_implementation.cc',
         'gl_implementation.h',
         'gl_implementation_android.cc',
-        'gl_implementation_linux.cc',
         'gl_implementation_mac.cc',
         'gl_implementation_win.cc',
+        'gl_implementation_x11.cc',
         'gl_interface.cc',
         'gl_interface.h',
         'gl_osmesa_api_implementation.cc',
@@ -103,11 +103,11 @@
         'gl_surface.cc',
         'gl_surface.h',
         'gl_surface_android.cc',
-        'gl_surface_linux.cc',
         'gl_surface_mac.cc',
         'gl_surface_stub.cc',
         'gl_surface_stub.h',
         'gl_surface_win.cc',
+        'gl_surface_x11.cc',
         'gl_surface_osmesa.cc',
         'gl_surface_osmesa.h',
         'gl_switches.cc',
@@ -188,7 +188,7 @@
         },
       ],
       'conditions': [
-        ['OS != "mac"', {
+        ['OS in ("win", "android") or (OS == "linux" and use_x11 == 1)', {
           'sources': [
             'async_pixel_transfer_delegate_egl.cc',
             'async_pixel_transfer_delegate_egl.h',