Fix android depfiles to always list GN's outputs[0]

components/cronet/android/BUILD.gn

 # Copyright 2015 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/buildflag_header.gni")
 import("//build/config/android/config.gni")
 import("//build/config/android/rules.gni")
 import("//build/util/version.gni")
 import("//chrome/version.gni")
 import("//testing/test.gni")
@@ skipping 854 matching lines @@
   ]
   args = [
     "license",
     rebase_path(_license_path, root_build_dir),
   ]
 }
 
 action("generate_javadoc") {
   script = "//components/cronet/tools/generate_javadoc.py"
   depfile = "$target_gen_dir/$target_name.d"
+  _stamp_file = "$target_gen_dir/$target_name.stamp"
   outputs = [
-    depfile,
+    _stamp_file,
   ]
   args = [
     "--output-dir",
     rebase_path(_package_dir, root_build_dir),
     "--input-dir",
     rebase_path("//components/cronet", root_build_dir),
     "--overview-file",
     rebase_path("$_package_dir/README.md.html", root_build_dir),
     "--readme-file",
     rebase_path("//components/cronet/README.md", root_build_dir),
     "--depfile",
     rebase_path(depfile, root_build_dir),
+    "--stamp",
+    rebase_path(_stamp_file, root_build_dir),
     "--lib-java-dir",
     rebase_path("$root_build_dir/lib.java/components/cronet/android",
                 root_build_dir),
 
     # JavaDoc is generated from Cronet's API source jar.
     "--input-src-jar",
     rebase_path("$_package_dir/cronet_api-src.jar", root_build_dir),
   ]
   deps = [
     ":cronet_javadoc_classpath",
@@ skipping 90 matching lines @@
       ":jar_cronet_api_source",
       ":jar_cronet_other_source",
       ":jar_cronet_sample_source",
       ":repackage_extracted_jars",
     ]
     if (current_cpu == "arm" && arm_version == 7) {
       deps += [ ":enforce_no_neon" ]
     }
   }
 }