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

device/BUILD.gn

Index: device/BUILD.gn
diff --git a/device/BUILD.gn b/device/BUILD.gn
index 4961292c55c9fca030f0cd129ed5c294fe44783c..9991764680cf5eb65ba3ef928ad7c19f219cb416 100644
--- a/device/BUILD.gn
+++ b/device/BUILD.gn
@@ -69,11 +69,16 @@ test("device_unittests") {
     "//net",
     "//testing/gmock",
     "//testing/gtest",
-    "//third_party/mojo/src/mojo/edk/system",
     "//third_party/mojo/src/mojo/public/cpp/bindings",
     "//url",
   ]
 
+  if (use_chrome_edk) {
+    deps += [ "//mojo/edk/system" ]
+  } else {
+    deps += [ "//third_party/mojo/src/mojo/edk/system" ]
+  }
+
   if (!is_linux_without_dbus && !is_chromeos) {
     sources += [ "battery/battery_status_manager_linux_unittest.cc" ]
   }