[Android] Add option to add additional files to built jars.

build/config/android/internal_rules.gni

Index: build/config/android/internal_rules.gni
diff --git a/build/config/android/internal_rules.gni b/build/config/android/internal_rules.gni
index 363a53a1685f3274b7eddf7ec0f8a4c1bd449433..1abdd62663a3dea85625b16a3799b92f4541336e 100644
--- a/build/config/android/internal_rules.gni
+++ b/build/config/android/internal_rules.gni
@@ -1830,7 +1830,7 @@ if (enable_java_templates) {
     _enable_interface_jars_javac = true
     if (defined(invoker.processors_javac)) {
       _processors = invoker.processors_javac
-      _enable_iterface_jars_javac = _processors == []
+      _enable_interface_jars_javac = _processors == []
     }
 
     _processor_args = []
@@ -1838,6 +1838,11 @@ if (enable_java_templates) {
       _processor_args = invoker.processor_args_javac
     }
 
+    _additional_jar_files = []
+    if (defined(invoker.additional_jar_files)) {
+      _additional_jar_files = invoker.additional_jar_files
+    }
+
     if (defined(invoker.enable_incremental_javac_override)) {
       # Use invoker-specified override.
       _enable_incremental_javac = invoker.enable_incremental_javac_override
@@ -1970,6 +1975,9 @@ if (enable_java_templates) {
       foreach(e, _processor_args) {
         args += [ "--processor-arg=" + e ]
       }
+      foreach(e, _additional_jar_files) {
+        args += [ "--additional-jar-file=" + e ]
+      }
       if (invoker.java_files != []) {
         args += [ "@" + rebase_path(invoker.java_sources_file, root_build_dir) ]
       }
@@ -2178,6 +2186,7 @@ if (enable_java_templates) {
     compile_java(_compile_java_target) {
       forward_variables_from(invoker,
                              [
+                               "additional_jar_files",
                                "alternative_android_sdk_ijar",
                                "alternative_android_sdk_ijar_dep",
                                "dist_jar_path",