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

Making changes so that at build time scripts will be generated that can be used to easily run tests.

BUG=490781
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1120883002

Cr-Commit-Position: refs/heads/master@{#332518}

diff --git a/cc/BUILD.gn b/cc/BUILD.gn
index 66e8050..dfe9f121 100644
--- a/cc/BUILD.gn
+++ b/cc/BUILD.gn

@@ -962,6 +962,10 @@
     "//ui/gfx/geometry",
     "//ui/gl",
   ]
+
+  if (is_android) {
+    isolate_file = "cc_perftests.isolate"
+  }
 }
 # When adding support for isolates, please have a look at run-time dependencies
 # in the cc_unittests_run target in cc_tests.gyp.