[iOS testing] - Cut dependency from test module and app code.

The following can lead to ODR violations with symbols present in the
app and in the test module:

gn path out/Perf //:webrtc_perf_tests_module //sdk:helpers_objc

//:webrtc_perf_tests_module --[public]-->
//:webrtc_perf_tests_module_loadable_module --[private]-->
//test:google_test_runner_objc --[private]-->
//test:test_support_objc --[private]-->
//sdk:helpers_objc

After this CL:

gn path out/Debug/ //:webrtc_perf_tests_module //sdk:helpers_objc
No non-data paths found between these two targets.

Bug: b/292472934
Change-Id: If8a6ecab9b34bea0f52fe91b3404d1afeca685fe
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/313520
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Auto-Submit: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40481}
diff --git a/test/BUILD.gn b/test/BUILD.gn
index 4107162..e60febb 100644
--- a/test/BUILD.gn
+++ b/test/BUILD.gn
@@ -414,11 +414,11 @@
     sources = [
       "ios/coverage_util_ios.h",
       "ios/coverage_util_ios.mm",
-      "ios/google_test_runner_delegate.h",
       "ios/test_support.h",
       "ios/test_support.mm",
     ]
     deps = [
+      ":google_test_runner_delegate",
       ":perf_test",
       "../api/test/metrics:chrome_perf_dashboard_metrics_exporter",
       "../api/test/metrics:global_metrics_logger_and_exporter",
@@ -432,13 +432,17 @@
     configs += [ ":test_support_objc_config" ]
   }
 
+  rtc_library("google_test_runner_delegate") {
+    sources = [ "ios/google_test_runner_delegate.h" ]
+  }
+
   rtc_library("google_test_runner_objc") {
     testonly = true
     visibility = [ "*" ]
     sources = [ "ios/google_test_runner.mm" ]
-    deps = [ ":test_support_objc" ]
     configs += [ "//build/config/ios:xctest_config" ]
     frameworks = [ "UIKit.framework" ]
+    deps = [ ":google_test_runner_delegate" ]
   }
 
   config("test_support_objc_config") {