GN: Set --coverage-dir in bin/run_* script when emma_coverage = true

build/config/android/internal_rules.gni

 # 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/android/config.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/config/zip.gni")
 import("//third_party/ijar/ijar.gni")
 
 assert(is_android)
@@ skipping 1973 matching lines @@
       _build_config =
           get_label_info(invoker.apk_target, "target_gen_dir") + "/" +
           get_label_info(invoker.apk_target, "name") + ".build_config"
       _rebased_build_config = rebase_path(_build_config, root_build_dir)
       test_runner_args += [
         "--test-apk",
         "@FileArg($_rebased_build_config:deps_info:apk_path)",
         "--apk-under-test",
         "@FileArg($_rebased_build_config:deps_info:tested_apk_path)",
       ]
+      if (emma_coverage) {
+        # Set a default coverage output directory (can be overridden by user
+        # passing the same flag).
+        test_runner_args += [
+          "--coverage-dir",
+          rebase_path("$root_out_dir/coverage", root_build_dir),
+        ]
+      }
     } else {
       assert(false, "Invalid test type: $_test_type.")
     }
 
     if (defined(invoker.isolate_file)) {
       test_runner_args += [
         "--isolate-file-path",
         rebase_path(invoker.isolate_file, root_build_dir),
       ]
     }
@@ skipping 18 matching lines @@
     ]
     args = [
       "--depfile",
       rebase_path(depfile, root_build_dir),
       "--script-output-path",
       rebase_path(generated_script, root_build_dir),
     ]
     args += test_runner_args
   }
 }