Get 'gn_all' building on iOS

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 9845ff4d20ec7b3d8012d68f6274a15c1aa6f375..42228cddf56cd0404b9c299f7335081d258b322a 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -12,6 +12,7 @@ import("//build/config/features.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/config/ui.gni")
 import("//build_overrides/v8.gni")
+import("//build_overrides/webrtc.gni")
 import("//media/media_options.gni")
 import("//third_party/openh264/openh264_args.gni")
 
@@ -205,17 +206,22 @@ group("both_gn_and_gyp") {
     ]
   } else {
     deps += [
-      "//ios/chrome:ios_chrome_unittests",
-      "//ios/chrome/app",
-      "//ios/chrome/browser",
-      "//ios/chrome/common",
       "//ios/net:ios_net_unittests",
-      "//ios/public/provider/chrome/browser",
       "//ios/public/provider/web",
       "//ios/testing:ocmock_support_unittest",
       "//ios/web:ios_web_unittests",
       "//ios/web/shell:ios_web_shell",
     ]
+
+    if (ios_use_webrtc) {
+      deps += [
+        "//ios/chrome:ios_chrome_unittests",
+        "//ios/chrome/app",
+        "//ios/chrome/browser",
+        "//ios/chrome/common",
+        "//ios/public/provider/chrome/browser",
+      ]
+    }
   }
 
   deps += root_extra_deps
@@ -586,7 +592,7 @@ group("both_gn_and_gyp") {
     deps += [ "//chromecast:cast_shell" ]
   }
 
-  if (is_ios || is_mac) {
+  if (is_mac) {  # TODO(GYP) || is_ios
     deps += [ "//media/cast:cast_h264_vt_encoder_unittests" ]
   }