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 9e8568e779d81c3baecf7bfe02de60f12a706646..fc5a19d306c7246ae58091c70eb0fe7aa5ca4357 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -1470,6 +1470,12 @@ 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 = "$base_path.proguard.jar"
+  }
+
   build_config_target = "${_template_name}__build_config"
   write_build_config(build_config_target) {
     type = "android_apk"
@@ -1487,11 +1493,17 @@ 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 = []
 
+  _generated_proguard_config = "$base_path.resources.proguard.txt"
   process_resources_target = "${_template_name}__process_resources"
   final_deps += [ ":$process_resources_target" ]
   process_resources(process_resources_target) {
@@ -1502,6 +1514,7 @@ 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
 
     if (defined(invoker.include_all_resources)) {
       include_all_resources = invoker.include_all_resources
@@ -1610,14 +1623,43 @@ template("android_apk") {
     }
   }
 
+  if (defined(invoker.proguard_enabled) && invoker.proguard_enabled) {
+    _proguard_configs = [ _generated_proguard_config ]
+    if (defined(invoker.proguard_configs)) {
+      _proguard_configs += invoker.proguard_configs
+    }
+    proguard_target = "${_template_name}__proguard"
+    proguard(proguard_target) {
+      deps = [
+        ":$build_config_target",
+        ":$process_resources_target",
+        ":$java_target",
+      ]
+      inputs = [
+                 _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($_rebased_build_config:proguard:input_paths)",
+      ]
+    }
+    dex_jar_path = _proguard_jar_path
+    dex_deps = [ ":$proguard_target" ]
+  } else {
+    dex_jar_path = jar_path
+    dex_deps = [ ":$java_target" ]
+  }
+
   final_deps += [ ":$final_dex_target_name" ]
   dex("$final_dex_target_name") {
-    deps = [
-      ":$build_config_target",
-      ":$java_target",
-    ]
+    deps = dex_deps + [ ":$build_config_target" ]
     sources = [
-      jar_path,
+      dex_jar_path,
     ]
     inputs = [
       _build_config,
@@ -1881,6 +1923,9 @@ template("instrumentation_test_apk") {
     if (defined(invoker.native_libs)) {
       native_libs = invoker.native_libs
     }
+    if (defined(invoker.proguard_enabled)) {
+      proguard_enabled = invoker.proguard_enabled
+    }
     if (defined(invoker.apk_under_test)) {
       apk_under_test = invoker.apk_under_test
     }