Reland x2 "[Android] Remove most resource names in resources.arsc"

This reverts commit 65f0e20a.

Reason for reland: Fixes crbug.com/900909 and crbug.com/900993

TBR=torne@chromium.org (No changes in webview section)

Original change's description:
> [Android] Remove most resource names in resources.arsc
>
> resource names are stored in the resources.arsc file to allow for
> getIdentifier with the string name of the resource to work. This cl
> obfuscates all of those resources to one name (and thus stored only
> once) for all resources that are not accessed via getIdentifier.
>
> This improves binary size by about 200KB.
>
> Bug: 894208
>
> Change-Id: I28c440c22b90cd045f53017073fdb88c7410d530
> Reviewed-on: https://chromium-review.googlesource.com/c/1265897
> Commit-Queue: Mohamed Heikal <mheikal@chromium.org>
> Reviewed-by: Richard Coles <torne@chromium.org>
> Reviewed-by: agrieve <agrieve@chromium.org>
> Reviewed-by: Ted Choc <tedchoc@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#603229}
Bug: 894208, 900909, 900993

Change-Id: Ie1e8790b392b5cbfff6d207c11e12bed6b8cc765
Reviewed-on: https://chromium-review.googlesource.com/c/1316092Reviewed-by: Mohamed Heikal <mheikal@chromium.org>
Reviewed-by: agrieve <agrieve@chromium.org>
Commit-Queue: Mohamed Heikal <mheikal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605451}

android_webview/aapt2.config

+string/license_activity_title#no_obfuscate

android_webview/apk/java/src/com/android/webview/chromium/LicenseActivity.java

@@ -29,6 +29,9 @@ public class LicenseActivity extends Activity {
                 String.format("content://%s.%s", packageName, LICENSES_URI_SUFFIX);
         intent.setDataAndType(Uri.parse(licenseUri), LICENSES_CONTENT_TYPE);
         intent.addCategory(Intent.CATEGORY_DEFAULT);
+        // Resources are accessed via getIdentifier because resource ids in the standalone system
+        // webview apk have incorrect package_ids. Accessing resources via getIdentifier needs to be
+        // whitelisted in //android_webview/aapt2.config. see https://crbug.com/894208
         final int titleId =
                 getResources().getIdentifier("license_activity_title", "string", packageName);
         if (titleId != 0) {

build/android/gyp/apkbuilder.py

@@ -329,8 +329,9 @@ def main(args):
         resource_infos = resource_apk.infolist()
 
         # 1. AndroidManifest.xml
-        assert resource_infos[0].filename == 'AndroidManifest.xml'
-        copy_resource(resource_infos[0], out_dir=apk_manifest_dir)
+        copy_resource(
+            resource_apk.getinfo('AndroidManifest.xml'),
+            out_dir=apk_manifest_dir)
 
         # 2. Assets
         if options.write_asset_list:
@@ -380,8 +381,9 @@ def main(args):
           build_utils.AddToZipHermetic(out_apk, apk_path, data='')
 
         # 5. Resources
-        for info in resource_infos[1:]:
-          copy_resource(info)
+        for info in resource_infos:
+          if info.filename != 'AndroidManifest.xml':
+            copy_resource(info)
 
         # 6. Java resources that should be accessible via
         # Class.getResourceAsStream(), in particular parts of Emma jar.

build/android/gyp/compile_resources.py

@@ -141,6 +141,17 @@ def _ParseArgs(args):
                           action='store_true',
                           help='Whether to strip xml namespaces from processed '
                                'xml resources')
+  input_opts.add_argument(
+      '--resources-config-path', help='Path to aapt2 resources config file.')
+  input_opts.add_argument(
+      '--optimize-resources',
+      default=False,
+      action='store_true',
+      help='Whether to run the `aapt2 optimize` step on the resources.')
+  input_opts.add_argument(
+      '--unoptimized-resources-path',
+      help='Path to output the intermediate apk before running '
+      '`aapt2 optimize`.')
 
   input_opts.add_argument(
       '--check-resources-pkg-id', type=_PackageIdArgument,
@@ -306,7 +317,6 @@ def _CreateLinkApkArgs(options):
     '--version-name', options.version_name,
     '--auto-add-overlay',
     '--no-version-vectors',
-    '-o', options.apk_path,
   ]
 
   for j in options.include_resources:
@@ -481,7 +491,11 @@ def _CompileDeps(aapt2_path, dep_subdirs, temp_dir):
     partial_path = os.path.join(partials_dir, dirname + '.zip')
     compile_command = (partial_compile_command +
                        ['--dir', directory, '-o', partial_path])
-    build_utils.CheckOutput(compile_command)
+    build_utils.CheckOutput(
+        compile_command,
+        stderr_filter=lambda output:
+            build_utils.FilterLines(
+                output, r'ignoring configuration .* for styleable'))
 
     # Sorting the files in the partial ensures deterministic output from the
     # aapt2 link step which uses order of files in the partial.
@@ -541,7 +555,15 @@ def _PackageApk(options, dep_subdirs, temp_dir, gen_dir, r_txt_path):
   for directory in dep_subdirs:
     renamed_paths.update(_MoveImagesToNonMdpiFolders(directory))
 
+  if options.optimize_resources:
+    if options.unoptimized_resources_path:
+      unoptimized_apk_path = options.unoptimized_resources_path
+    else:
+      unoptimized_apk_path = os.path.join(gen_dir, 'intermediate.ap_')
+  else:
+    unoptimized_apk_path = options.apk_path
   link_command = _CreateLinkApkArgs(options)
+  link_command += ['-o', unoptimized_apk_path]
   link_command += ['--output-text-symbols', r_txt_path]
   # TODO(digit): Is this below actually required for R.txt generation?
   link_command += ['--java', gen_dir]
@@ -557,10 +579,69 @@ def _PackageApk(options, dep_subdirs, temp_dir, gen_dir, r_txt_path):
   # Also creates R.txt
   build_utils.CheckOutput(
       link_command, print_stdout=False, print_stderr=False)
+
+  if options.optimize_resources:
+    _OptimizeApk(options, temp_dir, unoptimized_apk_path, r_txt_path)
+
   _CreateResourceInfoFile(
       renamed_paths, options.apk_info_path, options.dependencies_res_zips)
 
 
+def _OptimizeApk(options, temp_dir, unoptimized_apk_path, r_txt_path):
+  """Optimize intermediate .ap_ file with aapt2.
+
+  Args:
+    options: The command-line options tuple. E.g. the generated apk
+      will be written to |options.apk_path|.
+    temp_dir: A temporary directory.
+    unoptimized_apk_path: path of the apk to optimize.
+    r_txt_path: path to the R.txt file of the unoptimized apk.
+  """
+  # Resources of type ID are references to UI elements/views. They are used by
+  # UI automation testing frameworks. They are kept in so that they dont break
+  # tests, even though they may not actually be used during runtime. See
+  # https://crbug.com/900993
+  id_resources = _ExtractIdResources(r_txt_path)
+  gen_config_path = os.path.join(temp_dir, 'aapt2.config')
+  if options.resources_config_path:
+    shutil.copyfile(options.resources_config_path, gen_config_path)
+  with open(gen_config_path, 'a+') as config:
+    for resource in id_resources:
+      config.write('{}#no_obfuscate\n'.format(resource))
+
+  # Optimize the resources.arsc file by obfuscating resource names and only
+  # allow usage via R.java constant.
+  optimize_command = [
+      options.aapt2_path,
+      'optimize',
+      '--enable-resource-obfuscation',
+      '-o',
+      options.apk_path,
+      '--resources-config-path',
+      gen_config_path,
+      unoptimized_apk_path,
+  ]
+  build_utils.CheckOutput(
+      optimize_command, print_stdout=False, print_stderr=False)
+
+
+def _ExtractIdResources(rtxt_path):
+  """Extract resources of type ID from the R.txt file
+
+  Args:
+    rtxt_path: Path to R.txt file with all the resources
+  Returns:
+    List of id resources in the form of id/<resource_name>
+  """
+  id_resources = []
+  with open(rtxt_path) as rtxt:
+    for line in rtxt:
+      if ' id ' in line:
+        resource_name = line.split()[2]
+        id_resources.append('id/{}'.format(resource_name))
+  return id_resources
+
+
 def _WriteFinalRTxtFile(options, aapt_r_txt_path):
   """Determine final R.txt and return its location.
 
@@ -639,25 +720,27 @@ def main(args):
   # Order of these must match order specified in GN so that the correct one
   # appears first in the depfile.
   possible_output_paths = [
-    options.apk_path,
-    options.apk_path + '.info',
-    options.r_text_out,
-    options.srcjar_out,
-    options.proguard_file,
-    options.proguard_file_main_dex,
+      options.apk_path,
+      options.apk_path + '.info',
+      options.r_text_out,
+      options.srcjar_out,
+      options.proguard_file,
+      options.proguard_file_main_dex,
+      options.unoptimized_resources_path,
   ]
   output_paths = [x for x in possible_output_paths if x]
 
   # List python deps in input_strings rather than input_paths since the contents
   # of them does not change what gets written to the depsfile.
   input_strings = options.extra_res_packages + [
-    options.shared_resources,
-    options.resource_blacklist_regex,
-    options.resource_blacklist_exceptions,
-    str(options.debuggable),
-    str(options.png_to_webp),
-    str(options.support_zh_hk),
-    str(options.no_xml_namespaces),
+      options.shared_resources,
+      options.resource_blacklist_regex,
+      options.resource_blacklist_exceptions,
+      str(options.debuggable),
+      str(options.png_to_webp),
+      str(options.support_zh_hk),
+      str(options.no_xml_namespaces),
+      str(options.optimize_resources),
   ]
 
   input_strings.extend(_CreateLinkApkArgs(options))
@@ -669,11 +752,12 @@ def main(args):
 
 
   possible_input_paths = [
-    options.aapt_path,
-    options.aapt2_path,
-    options.android_manifest,
-    debug_temp_resources_dir,
-    options.shared_resources_whitelist,
+      options.aapt_path,
+      options.aapt2_path,
+      options.android_manifest,
+      debug_temp_resources_dir,
+      options.shared_resources_whitelist,
+      options.resources_config_path,
   ]
   possible_input_paths += options.include_resources
   input_paths = [x for x in possible_input_paths if x]

build/config/android/internal_rules.gni

@@ -1981,14 +1981,15 @@ if (enable_java_templates) {
       outputs = []
 
       _android_aapt_path = android_default_aapt_path
+      _android_aapt2_path = android_sdk_tools_bundle_aapt2
       if (_proto_format) {
-        _android_aapt2_path = android_sdk_tools_bundle_aapt2
         depfile = "$target_gen_dir/${invoker.target_name}_3.d"
       }
 
       inputs = [
         invoker.build_config,
         _android_aapt_path,
+        _android_aapt2_path,
       ]
 
       _rebased_build_config = rebase_path(invoker.build_config, root_build_dir)
@@ -1999,19 +2000,13 @@ if (enable_java_templates) {
         "--include-resources=@FileArg($_rebased_build_config:android:sdk_jars)",
         "--aapt-path",
         rebase_path(_android_aapt_path, root_build_dir),
+        "--aapt2-path",
+        rebase_path(_android_aapt2_path, root_build_dir),
         "--dependencies-res-zips=@FileArg($_rebased_build_config:resources:dependency_zips)",
         "--extra-res-packages=@FileArg($_rebased_build_config:resources:extra_package_names)",
         "--extra-r-text-files=@FileArg($_rebased_build_config:resources:extra_r_text_files)",
       ]
 
-      if (_proto_format) {
-        inputs += [ _android_aapt2_path ]
-        args += [
-          "--aapt2-path",
-          rebase_path(_android_aapt2_path, root_build_dir),
-        ]
-      }
-
       inputs += [ invoker.android_manifest ]
       args += [
         "--android-manifest",
@@ -2048,6 +2043,25 @@ if (enable_java_templates) {
         ]
       }
 
+      if (defined(invoker.optimize_resources) && invoker.optimize_resources) {
+        args += [ "--optimize-resources" ]
+        if (defined(invoker.resources_config_path)) {
+          inputs += [ invoker.resources_config_path ]
+          args += [
+            "--resources-config-path",
+            rebase_path(invoker.resources_config_path, root_build_dir),
+          ]
+        }
+
+        if (defined(invoker.unoptimized_resources_path)) {
+          args += [
+            "--unoptimized-resources-path",
+            rebase_path(invoker.unoptimized_resources_path, root_build_dir),
+          ]
+          outputs += [ invoker.unoptimized_resources_path ]
+        }
+      }
+
       # Useful to have android:debuggable in the manifest even for Release
       # builds. Just omit it for officai
       if (debuggable_apks) {
@@ -2501,6 +2515,13 @@ if (enable_java_templates) {
           get_label_info(_incremental_compile_resources_target_name,
                          "target_gen_dir") + "/AndroidManifest.xml"
 
+      if (defined(invoker.unoptimized_resources_path)) {
+        _incremental_packaged_resources_path =
+            invoker.unoptimized_resources_path
+      } else {
+        _incremental_packaged_resources_path = invoker.packaged_resources_path
+      }
+
       _rebased_build_config =
           rebase_path(invoker.assets_build_config, root_build_dir)
 
@@ -2511,7 +2532,7 @@ if (enable_java_templates) {
         inputs = [
           _android_manifest,
           invoker.assets_build_config,
-          invoker.packaged_resources_path,
+          _incremental_packaged_resources_path,
         ]
         outputs = [
           # Output the non-compiled manifest for easy debugging (as opposed to
@@ -2526,7 +2547,7 @@ if (enable_java_templates) {
           "--out-manifest",
           rebase_path(_incremental_android_manifest, root_build_dir),
           "--in-apk",
-          rebase_path(invoker.packaged_resources_path, root_build_dir),
+          rebase_path(_incremental_packaged_resources_path, root_build_dir),
           "--out-apk",
           rebase_path(_incremental_compiled_resources_path, root_build_dir),
           "--aapt-path",

build/config/android/rules.gni

@@ -1885,6 +1885,10 @@ if (enable_java_templates) {
   #     uncompressed in the APK. Must be unset or true if load_library_from_apk
   #     is set to true.
   #   uncompress_dex: Store final .dex files uncompressed in the apk.
+  #   optimize_resources: True if resource names should be stripped from the
+  #     resources.arsc file in the apk or module.
+  #   resources_config_path: Path to the aapt2 optimize config file that tags
+  #     resources with acceptable/non-acceptable optimizations.
   template("android_apk_or_module") {
     forward_variables_from(invoker, [ "testonly" ])
 
@@ -2125,6 +2129,13 @@ if (enable_java_templates) {
       _android_sdk_dep = "//third_party/android_tools:android_sdk_java"
     }
 
+    _optimize_resources =
+        defined(invoker.optimize_resources) && invoker.optimize_resources
+    if (_optimize_resources) {
+      _unoptimized_resources_path =
+          "$target_out_dir/$_template_name.unoptimized.ap_"
+    }
+
     _compile_resources_target = "${_template_name}__compile_resources"
     _compile_resources_rtxt_out =
         "${target_gen_dir}/${_compile_resources_target}_R.txt"
@@ -2137,6 +2148,7 @@ if (enable_java_templates) {
                                "aapt_locale_whitelist",
                                "resource_blacklist_regex",
                                "resource_blacklist_exceptions",
+                               "resources_config_path",
                                "png_to_webp",
                                "no_xml_namespaces",
                              ])
@@ -2154,6 +2166,10 @@ if (enable_java_templates) {
         proguard_file_main_dex = _generated_proguard_main_dex_config
       }
       output = _packaged_resources_path
+      if (_optimize_resources) {
+        optimize_resources = true
+        unoptimized_resources_path = _unoptimized_resources_path
+      }
 
       build_config = _build_config
       deps = _deps + [
@@ -2590,6 +2606,9 @@ if (enable_java_templates) {
         if (_incremental_allowed) {
           android_manifest = _android_manifest
           base_path = _base_path
+          if (_optimize_resources) {
+            unoptimized_resources_path = _unoptimized_resources_path
+          }
         }
 
         # Incremental apk does not use native libs nor final dex.
@@ -2863,6 +2882,7 @@ if (enable_java_templates) {
                                "never_incremental",
                                "no_build_hooks",
                                "no_xml_namespaces",
+                               "optimize_resources",
                                "png_to_webp",
                                "post_process_package_resources_script",
                                "product_version_resources_dep",
@@ -2871,6 +2891,7 @@ if (enable_java_templates) {
                                "proguard_jar_path",
                                "resource_blacklist_regex",
                                "resource_blacklist_exceptions",
+                               "resources_config_path",
                                "secondary_abi_loadable_modules",
                                "secondary_abi_shared_libraries",
                                "secondary_native_lib_placeholders",
@@ -2961,6 +2982,7 @@ if (enable_java_templates) {
                                "native_lib_version_rule",
                                "negative_main_dex_globs",
                                "no_xml_namespaces",
+                               "optimize_resources",
                                "png_to_webp",
                                "product_version_resources_dep",
                                "proguard_configs",
@@ -2968,6 +2990,7 @@ if (enable_java_templates) {
                                "proguard_jar_path",
                                "resource_blacklist_regex",
                                "resource_blacklist_exceptions",
+                               "resources_config_path",
                                "secondary_abi_loadable_modules",
                                "secondary_abi_shared_libraries",
                                "secondary_native_lib_placeholders",

chrome/android/chrome_public_apk_tmpl.gni

@@ -111,6 +111,8 @@ template("chrome_public_common_apk_or_module_tmpl") {
     # Use zh-TW strings for zh-HK (https://crbug.com/780847).
     support_zh_hk = true
 
+    optimize_resources = true
+
     if (defined(shared_libraries) && shared_libraries != []) {
       _native_lib_file =
           rebase_path("$root_gen_dir/CHROME_VERSION.json", root_out_dir)
@@ -231,6 +233,9 @@ template("monochrome_public_common_apk_or_module_tmpl") {
     # Webview supports all locales (has no omitted ones).
     aapt_locale_whitelist = locales
 
+    # Resources config for blocklisting resource names from obfuscation
+    resources_config_path = "//android_webview/aapt2.config"
+
     if (!defined(invoker.target_type) || invoker.target_type == "android_apk") {
       # Incremental install doesn't work for monochrome. See crbug.com/663492.
       never_incremental = true