Fix running unittests on iOS simulator

webrtc/test/BUILD.gn

Index: webrtc/test/BUILD.gn
diff --git a/webrtc/test/BUILD.gn b/webrtc/test/BUILD.gn
index 0d234cd6e3eb24d9d779b74219dd916363ad9200..e4c67b36c52004500ff3d63423b3a432c3aca1aa 100644
--- a/webrtc/test/BUILD.gn
+++ b/webrtc/test/BUILD.gn
@@ -162,9 +162,10 @@ if (!build_with_chromium) {
   # so if a target depends on this BUILD.gn file we hit this error.
   rtc_source_set("test_main") {
     testonly = true
-    sources = [
-      "test_main.cc",
-    ]
+    sources = []
+    if (!is_ios) {
+      sources += [ "test_main.cc" ]
+    }
 
     public_deps = [
       ":test_support",
@@ -177,6 +178,12 @@ if (!build_with_chromium) {
       "//testing/gtest",
       "//third_party/gflags",
     ]
+
+    # TODO(oprypin): Bug 7758: integrate the iOS unittest support into WebRTC's
+    # test_main instead of replacing it with Chromium's main function.
+    if (is_ios) {
+      deps += [ "//base/test:run_all_unittests" ]
+    }
   }
 
   rtc_source_set("video_test_support") {