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

ipc/mojo/BUILD.gn

Index: ipc/mojo/BUILD.gn
diff --git a/ipc/mojo/BUILD.gn b/ipc/mojo/BUILD.gn
index d801a7b9c19ca16ed9b418eb258d39645651fd84..48b134c9409603594a42f3a517d55d39df7d3b50 100644
--- a/ipc/mojo/BUILD.gn
+++ b/ipc/mojo/BUILD.gn
@@ -39,11 +39,16 @@ component("mojo") {
     "//base/third_party/dynamic_annotations",
     "//ipc",
     "//mojo/environment:chromium",
-    "//third_party/mojo/src/mojo/edk/system",
     "//third_party/mojo/src/mojo/public/c/environment:environment",
     "//third_party/mojo/src/mojo/public/cpp/bindings",
     ":client_channel",
   ]
+
+  if (use_chrome_edk) {
+    deps += [ "//mojo/edk/system" ]
+  } else {
+    deps += [ "//third_party/mojo/src/mojo/edk/system" ]
+  }
 }
 
 test("ipc_mojo_unittests") {
@@ -63,9 +68,14 @@ test("ipc_mojo_unittests") {
     "//ipc/mojo",
     "//mojo/environment:chromium",
     "//testing/gtest",
-    "//third_party/mojo/src/mojo/edk/system",
     "//url",
   ]
+
+  if (use_chrome_edk) {
+    deps += [ "//mojo/edk/system" ]
+  } else {
+    deps += [ "//third_party/mojo/src/mojo/edk/system" ]
+  }
 }
 
 test("ipc_mojo_perftests") {
@@ -82,7 +92,12 @@ test("ipc_mojo_perftests") {
     "//ipc:test_support",
     "//ipc/mojo",
     "//mojo/environment:chromium",
-    "//third_party/mojo/src/mojo/edk/system",
     "//url",
   ]
+
+  if (use_chrome_edk) {
+    deps += [ "//mojo/edk/system" ]
+  } else {
+    deps += [ "//third_party/mojo/src/mojo/edk/system" ]
+  }
 }