Fix in preparation of fat builds.

The "ios_bundle_data" target will need to create more intermediate
targets that will have to be in the visibility list, so use ":*"
as the visibility to restrict it to target defined in the same file.

BUG=603180

Review-Url: https://codereview.chromium.org/2127733002
Cr-Commit-Position: refs/heads/master@{#403912}

testing/test.gni

@@ -281,10 +281,7 @@ template("test") {
     _resources_bundle_data = target_name + "_resources_bundle_data"
 
     bundle_data(_resources_bundle_data) {
-      visibility = [
-        ":${_test_target}",
-        ":${_test_target}_generate_executable",
-      ]
+      visibility = [ ":*" ]
       sources = [
         "//testing/gtest_ios/Default.png",
       ]