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

extensions/shell/BUILD.gn

Index: extensions/shell/BUILD.gn
diff --git a/extensions/shell/BUILD.gn b/extensions/shell/BUILD.gn
index 06bf717200944e47499fd9f16706ba5691962f84..030b22253bb57ca404b57b85ee28d1bc5253f318 100644
--- a/extensions/shell/BUILD.gn
+++ b/extensions/shell/BUILD.gn
@@ -57,12 +57,17 @@ source_set("app_shell_lib") {
     "//mojo/environment:chromium",
     "//skia",
     "//third_party/WebKit/public:blink",
-    "//third_party/mojo/src/mojo/edk/system",
     "//ui/base",
     "//ui/base/ime",
     "//v8",
   ]
 
+  if (use_chrome_edk) {
+    deps += [ "//mojo/edk/system" ]
+  } else {
+    deps += [ "//third_party/mojo/src/mojo/edk/system" ]
+  }
+
   sources = rebase_path(app_shell_gypi_values.app_shell_lib_sources,
                         ".",
                         "//extensions/shell")