Enable more tests in GN build.

ui/compositor/BUILD.gn

Index: ui/compositor/BUILD.gn
diff --git a/ui/compositor/BUILD.gn b/ui/compositor/BUILD.gn
index 73010ee67ba0e0ac2c030c34d2f78e120c679a69..517af0f9f6f6fba33c2b566abc1c01d3986f628e 100644
--- a/ui/compositor/BUILD.gn
+++ b/ui/compositor/BUILD.gn
@@ -84,9 +84,7 @@ source_set("test_support") {
     "test/layer_animator_test_controller.h",
     "test/test_compositor_host.h",
     "test/test_compositor_host_mac.mm",
-    "test/test_compositor_host_ozone.cc",
     "test/test_compositor_host_win.cc",
-    "test/test_compositor_host_x11.cc",
     "test/test_layer_animation_delegate.cc",
     "test/test_layer_animation_delegate.h",
     "test/test_layer_animation_observer.cc",
@@ -118,6 +116,12 @@ source_set("test_support") {
     configs += [ "//build/config/linux:x11" ]
     deps += [ "//ui/gfx/x" ]
   }
+
+  if (use_ozone) {
+    sources += [ "test/test_compositor_host_ozone.cc" ]
+  } else if (use_x11) {
+    sources += [ "test/test_compositor_host_x11.cc" ]
+  }
 }
 
 # TODO(GYP) enable this when all dependencies are complete and it links.