[Android] Generate scripts at build time to run android tests.

chrome/test/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/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/module_args/v8.gni")
 import("//testing/test.gni")
@@ skipping 1286 matching lines @@
       ]
     }
 
     if (is_android) {
       deps -= [ "//third_party/libaddressinput" ]
 
       # Some android targets still depend on --gc-sections to link.
       # TODO: remove --gc-sections for Debug builds (crbug.com/159847).
       ldflags = [ "-Wl,--gc-sections" ]
       deps += [ "//testing/android/native_test:native_test_native_code" ]
+      isolate_file = "../unit_tests.isolate"
     } else {
       sources +=
           rebase_path(unit_gypi_values.chrome_unit_tests_non_android_sources,
                       ".",
                       "//chrome")
     }
     if (is_ios || is_chromeos) {
       sources -=
           [ "../browser/metrics/signin_status_metrics_provider_unittest.cc" ]
     }
@@ skipping 505 matching lines @@
     "//third_party/mojo/src/mojo/edk/system",
   ]
 
   if (!is_android && use_ash) {
     sources +=
         rebase_path(unit_gypi_values.chrome_test_support_unit_ash_sources,
                     ".",
                     "//chrome")
   }
 }