Add yet more GN isolates ...

ui/events/BUILD.gn

Index: ui/events/BUILD.gn
diff --git a/ui/events/BUILD.gn b/ui/events/BUILD.gn
index a690eff605d1990d457c5a19131366a3404f790d..4e499079a88a91ac0da9ead5ff6c1f83636dac27 100644
--- a/ui/events/BUILD.gn
+++ b/ui/events/BUILD.gn
@@ -296,6 +296,15 @@ source_set("test_support") {
   }
 }
 
+# TODO(GYP): Delete this after we've converted everything to GN.
+# The _run targets exist only for compatibility w/ GYP.
+group("events_unittests_run") {
+  testonly = true
+  deps = [
+    ":events_unittests",
+  ]
+}
+
 test("events_unittests") {
   sources = [
     "android/scroller_unittest.cc",
@@ -343,6 +352,8 @@ test("events_unittests") {
     ]
   }
 
+  data_deps = [ "//third_party/mesa:osmesa" ]
+
   include_dirs = [ "//testing/gmock/include" ]
 
   if (use_x11) {