Android: Add java files from android_apk targets

build/config/android/internal_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_overrides/build.gni")
 import("//build/config/android/config.gni")
 import("//build/config/dcheck_always_on.gni")
 import("//build/config/sanitizers/sanitizers.gni")
@@ skipping 2227 matching lines @@
   }
 
   template("java_library_impl") {
     set_sources_assignment_filter([])
     forward_variables_from(invoker, [ "testonly" ])
     _accumulated_deps = []
     if (defined(invoker.deps)) {
       _accumulated_deps = invoker.deps
     }
 
+    # Caller overriding build config must have valid java sources file if it has
+    # java files.
+    assert(!defined(invoker.override_build_config) ||
+           !defined(invoker.java_files) || defined(invoker.java_sources_file))
+
     assert(defined(invoker.java_files) || defined(invoker.srcjars) ||
            defined(invoker.srcjar_deps))
     _base_path = "$target_gen_dir/$target_name"
 
     if (defined(invoker.output_name)) {
       _output_name = invoker.output_name
     } else {
       _output_name = target_name
     }
 
@@ skipping 61 matching lines @@
       if (defined(invoker.dex_path)) {
         _dex_path = invoker.dex_path
       }
     }
 
     _java_files = []
     if (defined(invoker.java_files)) {
       _java_files += invoker.java_files
     }
     if (_java_files != []) {
-      _java_sources_file = "$_base_path.sources"
+      if (defined(invoker.java_sources_file)) {
+        _java_sources_file = invoker.java_sources_file
+      } else {
+        _java_sources_file = "$_base_path.sources"
+      }
       write_file(_java_sources_file, rebase_path(_java_files, root_build_dir))
     }
 
     # Define build_config_deps which will be a list of targets required to
     # build the _build_config.
     if (defined(invoker.override_build_config)) {
       _build_config = invoker.override_build_config
     } else {
       _build_config = _base_path + ".build_config"
       build_config_target_name = "${_template_name}__build_config"
@@ skipping 439 matching lines @@
         rebase_path(root_build_dir, root_build_dir),
         "--packed-libraries-dir",
         rebase_path(_packed_libraries_dir, root_build_dir),
         "--libraries=${invoker.libraries_filearg}",
         "--filelistjson",
         rebase_path(invoker.file_list_json, root_build_dir),
       ]
     }
   }
 }