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

net/BUILD.gn

Index: net/BUILD.gn
diff --git a/net/BUILD.gn b/net/BUILD.gn
index 0add477f94858f4f08e47b277b4dd461a70effab..7ea01c63b8d2bdd376f2229e25e2dabfa7d96ab4 100644
--- a/net/BUILD.gn
+++ b/net/BUILD.gn
@@ -1535,8 +1535,13 @@ test("net_unittests") {
       ":net_browser_services",
       ":net_utility_services",
       "//mojo/environment:chromium",
-      "//third_party/mojo/src/mojo/edk/system",
     ]
+
+    if (use_chrome_edk) {
+      deps += [ "//mojo/edk/system" ]
+    } else {
+      deps += [ "//third_party/mojo/src/mojo/edk/system" ]
+    }
   } else {
     sources -= [
       "dns/host_resolver_mojo_unittest.cc",