Enable proguard for apks

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 c516a8c6857711614a7c13f2295a55fc98e6ae1a..82d2781e4f042f769095024798f9fa8307b8b05d 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -1303,6 +1303,12 @@ template("android_apk") {
   # Help GN understand that _create_abi_split is not unused (bug in GN).
   assert(_create_abi_split || true)
 
+  _proguard_enabled = false
+  if (defined(invoker.proguard_enabled) && invoker.proguard_enabled) {
+    _proguard_enabled = true
+    _proguard_jar_path = "$base_path.proguard.jar"
+  }
+
   write_build_config("${_template_name}__build_config") {
     type = "android_apk"
     dex_path = final_dex_path
@@ -1318,12 +1324,18 @@ template("android_apk") {
       apk_under_test = invoker.apk_under_test
     }
 
+    if (_proguard_enabled) {
+      proguard_enabled = true
+      proguard_info = "$_proguard_jar_path.info"
+    }
+
     native_libs = _native_libs
   }
 
   final_deps = []
 
   final_deps += [ ":${_template_name}__process_resources" ]
+  _generated_proguard_config = "$base_path.resources.proguard.txt"
   process_resources("${_template_name}__process_resources") {
     srcjar_path = "${target_gen_dir}/${target_name}.srcjar"
     r_text_path = "${target_gen_dir}/${target_name}_R.txt"
@@ -1332,6 +1344,7 @@ template("android_apk") {
     zip_path = resources_zip_path
     all_resources_zip_path = _all_resources_zip_path
     generate_constant_ids = true
+    proguard_file = _generated_proguard_config
     build_config = _build_config
 
     if (defined(invoker.include_all_resources)) {
@@ -1421,12 +1434,36 @@ template("android_apk") {
   }
 
   final_deps += [ ":${_template_name}__final_dex" ]
+
+  dex_jar_path = jar_path
+  if (defined(invoker.proguard_enabled) && invoker.proguard_enabled) {
+    _proguard_configs = [ _generated_proguard_config ]
+    if (defined(invoker.proguard_configs)) {
+      _proguard_configs += invoker.proguard_configs
+    }
+    proguard("${_template_name}__proguard") {
+      inputs = [

[newt (away), 2015/05/29 01:43:04]

funky indentation. this would be more normal:

    inputs = [
      _build_config,
      jar_path,
    ] + _proguard_configs

+                 _build_config,
+                 jar_path,
+               ] + _proguard_configs
+
+      output_jar_path = _proguard_jar_path
+      rebased_proguard_configs = rebase_path(_proguard_configs, root_build_dir)
+      args = [
+        "--proguard-configs=$rebased_proguard_configs",
+        "--tested-apk-info=@FileArg($_rebased_build_config:proguard:tested_apk_info)",
+        "--input-paths=@FileArg($_rebased_build_config:proguard:input_paths)",
+      ]
+    }
+    dex_jar_path = _proguard_jar_path
+  }
+
   dex("${_template_name}__final_dex") {
     deps = [
       ":${_template_name}__java",
     ]
     sources = [
-      jar_path,
+      dex_jar_path,
     ]
     inputs = [
       _build_config,