Add a variable indicating the target as Android M or later.

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/config/sanitizers/sanitizers.gni")
 import("//build/toolchain/toolchain.gni")
 import("//third_party/android_platform/config.gni")
@@ skipping 1249 matching lines @@
 #     (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".
 #   write_asset_list: Adds an extra file to the assets, which contains a list of
 #     all other asset files.
 #   alternative_locale_resource_dep: The locale resource target which overrides
 #     any exsting locale resources in dep graph.
+#   requires_sdk_api_level_23: If defined and true, the apk is intended for
+#     installation only on Android M or later. In these releases the system
+#     linker does relocation unpacking, so we can enable it unconditionally.
 #
 #   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.
 #
 # Example
 #   android_apk("foo_apk") {
 #     android_manifest = "AndroidManifest.xml"
 #     java_files = [
 #       "android/org/chromium/foo/FooApplication.java",
@@ skipping 78 matching lines @@
   if (defined(invoker.srcjar_deps)) {
     _srcjar_deps += invoker.srcjar_deps
   }
 
   _use_chromium_linker =
       defined(invoker.use_chromium_linker) && invoker.use_chromium_linker
   _enable_relocation_packing = defined(invoker.enable_relocation_packing) &&
                                invoker.enable_relocation_packing
   _load_library_from_apk =
       defined(invoker.load_library_from_apk) && invoker.load_library_from_apk
+  _requires_sdk_api_level_23 = defined(invoker.requires_sdk_api_level_23) &&
+                               invoker.requires_sdk_api_level_23
 
   assert(_use_chromium_linker || true)  # Mark as used.
+  assert(_requires_sdk_api_level_23 || true)
   if (_enable_relocation_packing) {
-    assert(_use_chromium_linker,
-           "enable_relocation_packing requires use_chromium_linker")
+    assert(_use_chromium_linker || _requires_sdk_api_level_23,
+           "enable_relocation_packing requires either use_chromium_linker " +
+               "or requires_sdk_api_level_23")
   }
   if (_load_library_from_apk) {
-    assert(_use_chromium_linker,
-           "load_library_from_apk requires use_chromium_linker")
+    assert(_use_chromium_linker || _requires_sdk_api_level_23,
+           "load_library_from_apk requires use_chromium_linker " +
+               "or requires_sdk_api_level_23")
   }
 
   # The dependency that makes the chromium linker, if any is needed.
   _native_libs_deps = []
 
   if (defined(invoker.native_libs) && invoker.native_libs != []) {
     if (is_component_build || is_asan) {
       _native_libs += [ "$root_shlib_dir/libc++_shared.so" ]
       _native_libs_deps += [ "//build/android:cpplib_stripped" ]
     }
@@ skipping 1029 matching lines @@
       "--target",
       rebase_path(invoker.target, root_build_dir),
       "--output-directory",
       rebase_path(root_out_dir, root_build_dir),
     ]
     if (defined(invoker.flag_name)) {
       args += [ "--flag-name=${invoker.flag_name}" ]
     }
   }
 }