Port placeholders logic GYP->GN

build/config/android/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("//base/android/linker/config.gni")
 import("//build/config/android/config.gni")
 import("//build/config/android/internal_rules.gni")
 import("//build/toolchain/toolchain.gni")
 import("//third_party/android_platform/config.gni")
 import("//tools/grit/grit_rule.gni")
@@ skipping 1168 matching lines @@
 #     (and so not through builtin targets like 'action', 'group', etc).
 #   java_files: List of .java files to include in the apk.
 #   srcjar_deps: List of srcjar dependencies. The .java files in the srcjars
 #      will be added to java_files and be included in this apk.
 #   apk_name: Name for final apk.
 #   final_apk_path: Path to final built apk. Default is
 #     $root_out_dir/apks/$apk_name.apk. Setting this will override apk_name.
 #   native_libs: List paths of native libraries to include in this apk. If these
 #     libraries depend on other shared_library targets, those dependencies will
 #     also be included in the apk.
+#   native_lib_placeholders: List of placeholder filenames to add to the apk
+#     (optional).
 #   apk_under_test: For an instrumentation test apk, this is the target of the
 #     tested apk.
 #   include_all_resources - If true include all resource IDs in all generated
 #     R.java files.
 #   testonly: Marks this target as "test-only".
 #
 #   DEPRECATED_java_in_dir: Directory containing java files. All .java files in
 #     this directory will be included in the library. This is only supported to
 #     ease the gyp->gn conversion and will be removed in the future.
 #
@@ skipping 449 matching lines @@
 
     # This target generates the input file _all_resources_zip_path.
     deps += _android_manifest_deps + [
               ":$build_config_target",
               ":$process_resources_target",
               ":$final_dex_target_name",
             ]
 
     if (_native_libs != [] && !_create_abi_split) {
       native_libs_dir = _native_libs_dir
+
+      # Placeholders are not necessary for L+, so add them here, but don't
+      # bother to create them in the case of splits.

[pkotwicz, 2015/11/16 19:28:22]

Can you mention the relevant bug in the comment? I think that
http://crbug.com/395038 is the correct bug

[agrieve, 2015/11/16 19:45:15]

Done.

+      forward_variables_from(invoker, [ "native_lib_placeholders" ])

[pkotwicz, 2015/11/16 19:28:22]

Nit: new line

[agrieve, 2015/11/16 19:45:15]

Done.

       deps += [ ":$_prepare_native_target_name" ]
     }
   }
 
   if (_native_libs != [] && _create_abi_split) {
     _manifest_rule = "${_template_name}__split_manifest_abi_${android_app_abi}"
     generate_split_manifest(_manifest_rule) {
       main_manifest = _android_manifest
       out_manifest =
           "$gen_dir/split-manifests/${android_app_abi}/AndroidManifest.xml"
@@ skipping 482 matching lines @@
   }
 
   android_library(target_name) {
     java_files = []
     srcjar_deps = [ ":${_template_name}__protoc_java" ]
     deps = [
       "//third_party/android_protobuf:protobuf_nano_javalib",
     ]
   }
 }