GN + Android: extract android_standalone_library rule.

build/config/android/rules.gni

Index: build/config/android/rules.gni
diff --git a/build/config/android/rules.gni b/build/config/android/rules.gni
index 5d0cb372388f729608e30c4c27e8dec2b8415e0d..e5ef0ee3f255906dcb14d11887d2a95c33ded87c 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -922,8 +922,6 @@ template("java_prebuilt") {
 #
 #   dex_path: If set, the resulting .dex.jar file will be placed under this
 #     path.
-#   standalone_dex_path: If set, a standalone .dex.jar containing the code from
-#     the library and all dependencies will be placed under this path.
 #
 #
 # Example
@@ -986,9 +984,6 @@ template("android_library") {
     if (defined(invoker.dex_path)) {
       dex_path = invoker.dex_path
     }
-    if (defined(invoker.standalone_dex_path)) {
-      standalone_dex_path = invoker.standalone_dex_path
-    }
 
     supports_android = true
     requires_android = true
@@ -1005,6 +1000,24 @@ template("android_library") {
   }
 }
 
+# Declare a target that packages a set of Java dependencies into a standalone
+# .dex.jar.
+#
+# Variables
+#   deps: specifies the dependencies of this target. Android libraries and
+#     resources in deps will be packaged into the resulting .dex.jar file.
+#   standalone_dex_path: optional override for the output file location.
+template("android_standalone_library") {
+  deps_dex(target_name) {
+    deps = invoker.deps
+    if (defined(invoker.standalone_dex_path)) {
+      standalone_dex_path = invoker.standalone_dex_path

[cjhopman, 2014/12/08 21:27:51]

I think you should require the invoker to specify the path for the dex.
Otherwise, the only useful way to use a target of this type would be to refer to
the generated output path and we typically don't want people doing that (because
we want to be free to change anything that the invoker doesn't specify).

Also, maybe just 'dex_path'.

[ppi, 2014/12/09 15:17:29]

Done.

+    } else {
+      standalone_dex_path = "$target_out_dir/$target_name.dex.jar"
+    }
+  }
+}
+
 # Declare an Android library target for a prebuilt jar
 #
 # This target creates an Android library containing java code and Android