Modules: Include VR native library in DFM

When enabled, this change will package the VR native library in the VR DFM.

Also, introduce a .gni that computes whether native libraries in modules is
enabled as a whole (not VR specific).

Bug: 921663
Change-Id: Iacf09c46393daf924059217b3c7b335822cedef6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1601535
Commit-Queue: Christopher Grant <cjgrant@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Tibor Goldschwendt <tiborg@chromium.org>
Reviewed-by: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#658347}

chrome/android/BUILD.gn

@@ -2232,6 +2232,7 @@ template("monochrome_or_trichrome_public_bundle_tmpl") {
       module_name = "Vr" + _bundle_name
       base_module_target = ":$_base_module_target_name"
       native_switches = _native_switches
+      is_monochrome_or_trichrome = true
       uncompress_shared_libraries = true
       version_code = _version_code
       version_name = _version_name

chrome/android/features/ar/ar_module_tmpl.gni

@@ -4,7 +4,7 @@
 
 import("//build/config/android/rules.gni")
 import("//build/config/locales.gni")
-import("//chrome/android/features/module_names_to_package_ids.gni")
+import("//chrome/android/features/dynamic_feature_modules.gni")
 import("//device/vr/buildflags/buildflags.gni")
 
 assert(enable_arcore)

chrome/android/features/autofill_assistant/autofill_assistant_module_tmpl.gni

 import("//build/config/android/rules.gni")
 import("//build/config/locales.gni")
-import("//chrome/android/features/module_names_to_package_ids.gni")
+import("//chrome/android/features/dynamic_feature_modules.gni")
 
 template("autofill_assistant_module_tmpl") {
   _manifest = "$target_gen_dir/$target_name/AndroidManifest.xml"

chrome/android/features/dynamic_feature_modules.gni

+# Copyright 2019 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/config/compiler/compiler.gni")
+import("//device/vr/buildflags/buildflags.gni")
+
+# This file aggregates data used when pulling DFM-related dependencies into
+# bundle builds. As DFMs move to describe their parameters in a standard way,
+# this file may evolve to an aggregation of individual DFM configurations.
+
+# Mapping that controls package IDs assigned to modules.
+resource_packages_id_mapping = [
+  "ar=0x7e",
+  "vr=0x7d",
+  "tab_ui=0x7c",
+  "autofill_assistant=0x7b",
+]
+
+# This variable indicates whether the native feature module system is engaged.
+# Currently, this implies a build configuration that supports native modules,
+# and that at least one feature is using a native module.
+if (is_clang && use_lld && !is_component_build) {
+  use_native_modules = enable_vr && modularize_vr_native
+} else {
+  use_native_modules = false
+}

chrome/android/features/module_names_to_package_ids.gni

-# Mapping that controls package IDs assigned to modules.
-resource_packages_id_mapping = [
-  "ar=0x7e",
-  "vr=0x7d",
-  "tab_ui=0x7c",
-  "autofill_assistant=0x7b",
-]

chrome/android/features/tab_ui/tab_ui_module_tmpl.gni

@@ -4,7 +4,7 @@
 
 import("//build/config/android/rules.gni")
 import("//build/config/locales.gni")
-import("//chrome/android/features/module_names_to_package_ids.gni")
+import("//chrome/android/features/dynamic_feature_modules.gni")
 
 template("tab_ui_module_tmpl") {
   assert(defined(invoker.version_code))

chrome/android/features/vr/vr_module_tmpl.gni

@@ -5,7 +5,7 @@
 import("//base/android/linker/config.gni")
 import("//build/config/android/rules.gni")
 import("//build/config/locales.gni")
-import("//chrome/android/features/module_names_to_package_ids.gni")
+import("//chrome/android/features/dynamic_feature_modules.gni")
 import("//device/vr/buildflags/buildflags.gni")
 
 assert(enable_vr)
@@ -45,9 +45,49 @@ template("vr_module_tmpl") {
       "//chrome/browser/android/vr:vr_ui_dummy_lib",
     ]
 
-    # TODO(crbug.com/943210): Remove this condition once downstream passes in
-    # native_switches.
-    if (defined(invoker.native_switches)) {
+    if (defined(invoker.is_monochrome_or_trichrome)) {
+      not_needed(invoker, [ "is_monochrome_or_trichrome" ])
+    }
+    if (use_native_modules && modularize_vr_native) {
+      # Include the VR native library. In relation to http://crbug.com/950056,
+      # this logic could be moved into a location common to all feature modules.
+      # This could be android_app_bundle_module(), or a Chrome-specific
+      # extension of it. In that case, this scope would potentially pass "vr"
+      # as a required native library, and the lower-level template would derive
+      # and include the correct library.
+      _is_monochrome_or_trichrome =
+          defined(invoker.is_monochrome_or_trichrome) &&
+          invoker.is_monochrome_or_trichrome
+      _arch = ""
+      _toolchain = ""
+      _root_out_dir = root_out_dir
+      if (android_64bit_target_cpu) {
+        if (defined(invoker.is_64_bit_browser) && invoker.is_64_bit_browser) {
+          _arch = "_64"
+        } else {
+          _toolchain = "($android_secondary_abi_toolchain)"
+          _root_out_dir =
+              get_label_info(":foo($android_secondary_abi_toolchain)",
+                             "root_out_dir")
+        }
+      }
+      if (_is_monochrome_or_trichrome) {
+        _base_target_name = "monochrome${_arch}_base"
+      } else {
+        _base_target_name = "libchrome${_arch}_base"
+      }
+      _module = "vr"
+      deps +=
+          [ "//chrome/android:${_base_target_name}_${_module}${_toolchain}" ]
+      _module_file =
+          "${_root_out_dir}/${_base_target_name}_partitions/lib${_module}.so"
+
+      # Pass the correct library as both the 32 and 64-bit options. Underlying
+      # logic will choose from the correct variable, and supply a dummy library
+      # for the other architecture if required.
+      loadable_modules_if_32_bit = [ _module_file ]
+      loadable_modules_if_64_bit = [ _module_file ]
+    } else {
       if (android_64bit_target_cpu) {
         _32_bit_toolchain_root_dir =
             get_label_info(":foo($android_secondary_abi_toolchain)",