NOT TO COMMITTED: Update mojo sdk to rev 0018e6a91b75bcb941c867f8a7aa1753c3b53a13

third_party/mojo/src/mojo/public/tools/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/module_args/mojo.gni")
 import("../mojo.gni")
 
 if (mojo_use_prebuilt_mojo_shell) {
   copy("copy_mojo_shell") {
     filename = "mojo_shell"
@@ skipping 40 matching lines @@
       }
     }
 
     outputs = [
       "$root_out_dir/$filename",
     ]
   }
 
   copy("copy_network_service_apptests") {
     filename = "network_service_apptests.mojo"
-    if (is_android) {
+    if (defined(mojo_prebuilt_network_service_apptests_location) &&
+        mojo_prebuilt_network_service_apptests_location != "") {
       sources = [
-        "prebuilt/network_service_apptests/android-arm/$filename",
+        "$mojo_prebuilt_network_service_apptests_location",
       ]
     } else {
-      assert(is_linux)
-      sources = [
-        "prebuilt/network_service_apptests/linux-x64/$filename",
-      ]
+      if (is_android) {
+        assert(
+            cpu_arch == "arm",
+            "Only arm version prebuilt netowrk_service_apptests.mojo is available.")
+        sources = [
+          "prebuilt/network_service_apptests/android-arm/$filename",
+        ]
+      } else {
+        assert(is_linux)
+        sources = [
+          "prebuilt/network_service_apptests/linux-x64/$filename",
+        ]
+      }
     }
     outputs = [
       "$root_out_dir/$filename",
     ]
   }
 }
 
 # This rule can be seen as a sort of adapter. This takes a dart framework
 # loaded from Google Storage and then puts it in a rule which the
 # "dart_package" template in mojo/public/dart/rules.gni can introspect on,
 # accessing the 'label' and 'target_out_dir' variables.
 if (mojo_use_dart_apptest_framework) {
   copy("dart_apptest_framework") {
     sources = [
       "prebuilt/frameworks/apptest.dartzip",
     ]
     outputs = [
       "$target_out_dir/dart_apptest_framework.dartzip",
     ]
   }
 }