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

content/common/BUILD.gn

Index: content/common/BUILD.gn
diff --git a/content/common/BUILD.gn b/content/common/BUILD.gn
index 36ad58e59ebe83967a570fdd7f828a1c850bd30e..8907aff43c928100084edc27d5cd5e4da2288b18 100644
--- a/content/common/BUILD.gn
+++ b/content/common/BUILD.gn
@@ -191,10 +191,15 @@ source_set("common") {
       "//sandbox",
       "//storage/common",
       "//third_party/WebKit/public:blink",
-      "//third_party/mojo/src/mojo/edk/system",
       "//ui/gl",
       ":mojo_bindings",
     ]
+
+    if (use_chrome_edk) {
+      deps += [ "//mojo/edk/system" ]
+    } else {
+      deps += [ "//third_party/mojo/src/mojo/edk/system" ]
+    }
   }
 
   defines = []