Add a Mojo EDK for Chrome that uses one OS pipe per message pipe.

content/app/BUILD.gn

Index: content/app/BUILD.gn
diff --git a/content/app/BUILD.gn b/content/app/BUILD.gn
index 463d9f18b4dd15ec076044cb559fe1c658980a6e..05a89e96bbf1fff3b6aca4564ca53bbf98aca282 100644
--- a/content/app/BUILD.gn
+++ b/content/app/BUILD.gn
@@ -63,8 +63,13 @@ if (is_ios) {
   content_app_deps += [
     "//mojo/application/public/interfaces",
     "//mojo/environment:chromium",
-    "//third_party/mojo/src/mojo/edk/system",
   ]
+
+  if (use_chrome_edk) {
+    content_app_deps += [ "//mojo/edk/system" ]
+  } else {
+    content_app_deps += [ "//third_party/mojo/src/mojo/edk/system" ]
+  }
 }
 
 content_app_extra_configs = [