[NOT FOR COMMIT] Added GN support for Android .AAR packaged libraries

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 4cb5b4d6bce6cdba26e10600cd815ca603f9fd11..ebca5a9c93fdc72ad39e646e8182c295e28eee99 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -2499,4 +2499,72 @@ if (enable_java_templates) {
       ]
     }
   }
+
+  # Declare an Android library target for a prebuilt aar
+  #
+  # This target creates an Android library containing java code and Android
+  # resources.
+  #
+  # Variables
+  #   aar_path: Path to the aar.
+  #
+  # Example
+  #   android_aar_prebuilt("foo_aar") {
+  #     aar_path = "foo.aar"
+  #   }
+  template("android_aar_prebuilt") {
+    assert(defined(invoker.aar_path))
+
+    _output_path = "${root_out_dir}/unpacked_aar/${target_name}"

[agrieve, 2016/06/28 19:36:05]

nit: should use "$target_gen_dir/$target_name"

+    _unpack_target_name = "${target_name}__unpack_aar"
+    _jar_target_name = "${target_name}__jar"
+    _res_target_name = "${target_name}__res"
+
+    action(_unpack_target_name) {
+      script = "//build/android/gyp/unpack_aar.py"  # Unzips the AAR
+      args = [
+        rebase_path(invoker.aar_path, root_build_dir),
+        rebase_path(_output_path, root_build_dir),
+      ]
+      outputs = [
+        "${_output_path}/AndroidManifest.xml",
+        "${_output_path}/classes.jar",
+        "${_output_path}/R.txt",
+      ]
+
+      _resource_files =
+          exec_script("//build/android/gyp/find.py",

[agrieve, 2016/06/28 19:36:05]

this runs at gn gen time, so won't actually find any files on the first build.

Might make sense to reuse unpack_aar.py and add a flag which just opens and
prints out the res/ directory listing.

+                      rebase_path([ "${_output_path}/res" ], root_out_dir),
+                      "list lines")
+
+      outputs += get_path_info(rebase_path(_resource_files, "", root_out_dir),
+                               "abspath")
+    }
+
+    java_prebuilt_impl(_jar_target_name) {

[agrieve, 2016/06/28 19:36:05]

would android_rebuilt() work here?

+      deps = [
+        ":$_unpack_target_name",
+      ]
+      jar_path = "${_output_path}/classes.jar"
+      supports_android = true
+      requires_android = true
+      strip_resource_classes = true
+    }
+
+    android_resources(_res_target_name) {
+      deps = [
+        ":$_unpack_target_name",
+      ]
+      resource_dirs = [ "${_output_path}/res" ]

[agrieve, 2016/06/28 19:36:06]

This also results in a find.py at gn gen time. I think what you need to do is:

resource_dirs = []
generated_resource_dirs = ["${_output_path}/res"]
generated_resource_files = _resource_files

+      android_manifest = "${_output_path}/AndroidManifest.xml"
+      v14_skip = true
+    }
+
+    java_group(target_name) {
+      deps = [
+        ":$_jar_target_name",
+        ":$_res_target_name",
+      ]
+    }
+  }
 }