Respect ios_automatically_manage_certs when building EG tests.

ios/chrome/test/earl_grey/chrome_ios_eg_test.gni

 # 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/mac/tweak_info_plist.gni")
 import("//ios/build/chrome_build.gni")
 import("//ios/public/provider/chrome/browser/build_config.gni")
 import("//ios/third_party/earl_grey/ios_eg_test.gni")
 
 # Template wrapping ios_eg_test, setting default values for EarlGrey test
@@ skipping 112 matching lines @@
     ]
     if (!defined(bundle_deps)) {
       bundle_deps = []
     }
     bundle_deps += [ "//ios/chrome/app/resources" ]
 
     if (!defined(extra_substitutions)) {
       extra_substitutions = []
     }
     extra_substitutions += [
-      "CHROMIUM_BUNDLE_ID=gtest.$target_name",
       "CHROMIUM_HANDOFF_ID=$chromium_handoff_id",
       "CHROMIUM_SHORT_NAME=$target_name",
       "CHROMIUM_URL_SCHEME_1=$url_unsecure_scheme",
       "CHROMIUM_URL_SCHEME_2=$url_secure_scheme",
       "CHROMIUM_URL_SCHEME_3=$url_x_callback_scheme",
       "CHROMIUM_URL_SCHEME_4=$url_channel_scheme",
       "EG_MAIN_APPLICATION_DELEGATE=$_eg_main_application_delegate",
       "SSOAUTH_URL_SCHEME=$url_ssoauth_scheme",
     ]
+    if (ios_automatically_manage_certs) {
+      # Use the same bundle identifier for EarlGrey tests as for unit tests
+      # when managing certificates as the number of free certs is limited.
+      extra_substitutions += [ "CHROMIUM_BUNDLE_ID=gtest.generic-unit-test" ]
+    } else {
+      extra_substitutions += [ "CHROMIUM_BUNDLE_ID=gtest.$target_name" ]
+    }
   }
 }