android_webview: support building a stub WebView.

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.
 
 # Do not add any imports to non-//build directories here.
 # Some projects (e.g. V8) do not have non-build directories DEPS'ed in.
 import("//build/config/android/config.gni")
 import("//build/config/android/internal_rules.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/dcheck_always_on.gni")
@@ skipping 1515 matching lines @@
 
     # The dependency that makes the chromium linker, if any is needed.
     _native_libs_deps = []
     _shared_libraries_is_valid =
         defined(invoker.shared_libraries) && invoker.shared_libraries != []
     _secondary_abi_native_libs_deps = []
     assert(_secondary_abi_native_libs_deps == [])  # mark as used.
     _secondary_abi_shared_libraries_is_valid =
         defined(invoker.secondary_abi_shared_libraries) &&
         invoker.secondary_abi_shared_libraries != []
+    _unpackaged_shared_libs = []
+    if (defined(invoker.unpackaged_shared_libraries)) {
+      _unpackaged_shared_libs += invoker.unpackaged_shared_libraries
+    }
 
     if (is_component_build || is_asan) {
       if (_shared_libraries_is_valid) {
         _native_libs_deps += [ "//build/android:cpplib_stripped" ]
       }
       if (_secondary_abi_shared_libraries_is_valid) {
         _secondary_abi_native_libs_deps += [ "//build/android:cpplib_stripped($android_secondary_abi_toolchain)" ]
       }
     }
 
     if (_shared_libraries_is_valid) {
       _native_libs_deps += invoker.shared_libraries
 
       # To determine the filenames of all dependent shared libraries, write the
       # runtime deps of |shared_libraries| to a file during "gn gen".
       # write_build_config.py will then grep this file for *.so to obtain the
       # complete list.
       _runtime_deps_file =
           "$target_gen_dir/${_template_name}.native.runtimedeps"
       group("${_template_name}__runtime_deps") {
         deps = _native_libs_deps
         write_runtime_deps = _runtime_deps_file
       }
-
-      _native_lib_version_rule = ""
-      if (defined(invoker.native_lib_version_rule)) {
-        _native_lib_version_rule = invoker.native_lib_version_rule
-      }
-      _native_lib_version_arg = "\"\""
-      if (defined(invoker.native_lib_version_arg)) {
-        _native_lib_version_arg = invoker.native_lib_version_arg
-      }
     }
 
     if (_secondary_abi_shared_libraries_is_valid) {
       _secondary_abi_native_libs_deps += invoker.secondary_abi_shared_libraries
 
       # To determine the filenames of all dependent shared libraries, write the
       # runtime deps of |shared_libraries| to a file during "gn gen".
       # write_build_config.py will then grep this file for *.so to obtain the
       # complete list.
       _secondary_abi_runtime_deps_file =
@@ skipping 114 matching lines @@
       proguard_file = _generated_proguard_config
 
       build_config = _build_config
       deps = _android_manifest_deps + [ ":$build_config_target" ]
       if (defined(invoker.deps)) {
         deps += invoker.deps
       }
     }
     _srcjar_deps += [ ":$process_resources_target" ]
 
-    if (_native_libs_deps != []) {
+    if (_native_libs_deps != [] || _unpackaged_shared_libs != []) {
+      _native_lib_version_rule = ""
+      if (defined(invoker.native_lib_version_rule)) {
+        _native_lib_version_rule = invoker.native_lib_version_rule
+      }
+      _native_lib_version_arg = "\"\""
+      if (defined(invoker.native_lib_version_arg)) {
+        _native_lib_version_arg = invoker.native_lib_version_arg
+      }
+
       _enable_chromium_linker_tests = false
       if (defined(invoker.enable_chromium_linker_tests)) {
         _enable_chromium_linker_tests = invoker.enable_chromium_linker_tests
       }
       _ordered_libraries_json =
-          "$target_gen_dir/$target_name.ordered_libararies.json"

[jbudorick, 2017/01/13 20:45:48]

:O

[Torne, 2017/01/16 12:49:01]

Yeah, I noticed that when looking in the out directory ;)

+          "$target_gen_dir/$target_name.ordered_libraries.json"
       _rebased_ordered_libraries_json =
           rebase_path(_ordered_libraries_json, root_build_dir)
       _ordered_libraries_target = "${_template_name}__write_ordered_libraries"
 
       # TODO(agrieve): Make GN write runtime deps in dependency order so as to
       # not need this manual sorting step.
       action(_ordered_libraries_target) {
         script = "//build/android/gyp/write_ordered_libraries.py"
         deps = _native_libs_deps + [ ":$build_config_target" ]

[jbudorick, 2017/01/13 20:45:48]

Can you add a comment noting why _unpackaged_shared_libs isn't listed in deps
here? While I think it's correct, I also think it'd be easy to come back at a
later time and mistakenly think otherwise.

[Torne, 2017/01/16 12:49:01]

Done.

         outputs = [
           _ordered_libraries_json,
         ]
         _rebased_android_readelf = rebase_path(android_readelf, root_build_dir)
         args = [
           "--readelf=$_rebased_android_readelf",
           "--output=$_rebased_ordered_libraries_json",
           "--libraries-dir=.",
           "--input-libraries=@FileArg($_rebased_build_config:native:libraries)",
+          "--unpackaged-libraries=$_unpackaged_shared_libs",
         ]
       }
 
       java_cpp_template("${_template_name}__native_libraries_java") {
         package_name = "org/chromium/base/library_loader"
         sources = [
           "//base/android/java/templates/NativeLibraries.template",
         ]
         inputs = [
           _ordered_libraries_json,
@@ skipping 1095 matching lines @@
         # because in practice they seem to contain classes required to be in the
         # classpath.
         deps += _subjar_targets
       }
       if (defined(_res_target_name)) {
         deps += [ ":$_res_target_name" ]
       }
     }
   }
 }