[iOS] Fix EarlGrey public configurations.

ios/third_party/earl_grey/BUILD.gn

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/ios/ios_sdk.gni")
 import("//build/config/ios/rules.gni")
 
 config("config") {
   include_dirs = [ "src/EarlGrey" ]
 }
@@ skipping 215 matching lines @@
     "src/EarlGrey/Provider/GREYDataEnumerator.h",
     "src/EarlGrey/Provider/GREYProvider.h",
     "src/EarlGrey/Synchronization/GREYNSTimerIdlingResource.h",
     "src/EarlGrey/Synchronization/GREYOperationQueueIdlingResource.h",
     "src/EarlGrey/Synchronization/GREYDispatchQueueIdlingResource.h",
     "src/EarlGrey/Synchronization/GREYSyncAPI.h",
     "src/EarlGrey/Synchronization/GREYCondition.h",
     "src/EarlGrey/Synchronization/GREYUIThreadExecutor.h",
   ]
   deps = [
+    "//build/config/ios:xctest",
     "//ios/third_party/fishhook",
     "//third_party/google_toolbox_for_mac",
   ]
   public_deps = [
     "//ios/third_party/ochamcrest:ochamcrest+link",
   ]
   precompiled_header = "src/EarlGrey.pch"
   precompiled_source = "src/EarlGrey.pch"
 
   libs = [
     "CoreGraphics.framework",
     "Foundation.framework",
     "IOKit.framework",
     "QuartzCore.framework",
     "UIKit.framework",
     "XCTest.framework",
   ]
 
-  public_configs = [
-    ":config",
-    "//build/config/ios:xctest_config",
+  public_configs = [ ":config" ]
+
+  configs -= [ "//build/config/gcc:symbol_visibility_hidden" ]
+  configs += [
+    "//build/config/compiler:enable_arc",
+    "//build/config/gcc:symbol_visibility_default",
   ]
-
-  configs += [ "//build/config/compiler:enable_arc" ]
-  configs -= [ "//build/config/gcc:symbol_visibility_hidden" ]
-  configs += [ "//build/config/gcc:symbol_visibility_default" ]
 }