[Build] Use GN write_file() instead of script to write .ssargs files.

Previously we added a script write_ssargs.py to write .ssargs files for
SuperSize. To simplify things, this CL removes the script, and use GN
write_file() command instead.

As a result .ssargs files are created on "gn gen", instead of during
build.

Bug: 1040645
Change-Id: I147480817d1c3036780d5496cc30fd2d4c8b9fb2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2267337
Commit-Queue: Samuel Huang <huangs@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#782728}

chrome/android/BUILD.gn

@@ -2808,10 +2808,7 @@ if (public_android_sdk) {
 
     # Used for binary size monitoring.
     create_app_bundle_minimal_apks("trichrome_chrome_minimal_apks") {
-      deps = [
-        ":ssargs_trichrome",
-        ":trichrome_chrome_bundle",
-      ]
+      deps = [ ":trichrome_chrome_bundle" ]
       bundle_path = "$root_build_dir/apks/TrichromeChrome.aab"
     }
 

chrome/android/trichrome.gni

@@ -210,23 +210,19 @@ template("trichrome_library_apk_tmpl") {
 # parameters, and is used by SuperSize-archive to create multi-container .size
 # files. This is used to support SuperSize on Trichrome.
 template("write_ssargs_trichrome") {
-  action(target_name) {
-    script = "//chrome/android/write_ssargs.py"
-    outputs = [ invoker.ssargs_path ]
-
-    # Base names (i.e., no full path) are used because .ssargs files specifies
-    # files using paths relative to itself. It is expected for |ssargs_path| to
-    # be in the same directory as all Trichrome files whose sizes are measured
-    # by SuperSize.
-    args = [
-      rebase_path(invoker.ssargs_path, root_build_dir),
-      "--items",
-      "Library -f ${invoker.trichrome_library_basename}",
-      "Chrome -f ${invoker.trichrome_chrome_basename}",
-
-      # WebView has no .so files. --java-only is needed to prevent SuperSize
-      # from failing.
-      "WebView -f ${invoker.trichrome_webview_basename} --java-only",
-    ]
-  }
+  # Base names (i.e., no full path) are used because .ssargs files specifies
+  # files using paths relative to itself. It is expected for |ssargs_path| to
+  # be in the same directory as all Trichrome files whose sizes are measured
+  # by SuperSize.
+  ssargs_lines = [
+    "# Written by build target \"${target_name}.\"",
+    "Library -f ${invoker.trichrome_library_basename}",
+    "Chrome -f ${invoker.trichrome_chrome_basename}",
+
+    # WebView has no .so files. --java-only is needed to prevent SuperSize
+    # from failing.
+    "WebView -f ${invoker.trichrome_webview_basename} --java-only",
+  ]
+
+  write_file(invoker.ssargs_path, ssargs_lines)
 }

chrome/android/write_ssargs.py

-#!/usr/bin/env python
-# Copyright 2020 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.
-"""Creates .ssargs file for SuperSize."""
-
-import argparse
-import os
-import sys
-
-
-def main():
-  parser = argparse.ArgumentParser()
-  parser.add_argument('output', type=argparse.FileType('w'),
-                      help='Output filename.')
-  parser.add_argument('--items',
-                      nargs='*',
-                      default=[],
-                      help='Line specifying a single Container.')
-  args = parser.parse_args()
-  lines = ['# Generated by {}'.format(os.path.basename(__file__))] + args.items
-  args.output.write('\n'.join(lines + ['']))
-
-
-if __name__ == '__main__':
-  main()