Refactor base's proguard flags to be more usable by cronet

chrome/android/webapk/shell_apk/BUILD.gn

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/rules.gni")
 import("shell_apk_version.gni")
 
 declare_args() {
   # The origin URL of the WebAPK. Used to generate a unique package name for
   # WebAPK. Example: "foo.com"
@@ skipping 98 matching lines @@
   android_manifest = shell_apk_manifest
   android_manifest_dep = ":shell_apk_manifest"
   apk_name = "WebApk.$webapk_manifest_package_origin"
   deps = [
     ":webapk_java",
   ]
   if (!is_java_debug) {
     proguard_enabled = true
     proguard_configs = [
       "//chrome/android/java/proguard.flags",
-      "//base/android/base_proguard_config.flags",
-      "//base/android/release_proguard_config.flags",
+      "//base/android/proguard/chromium_apk.flags",
+      "//base/android/proguard/chromium_code.flags",
     ]
   }
 }
 
 android_library("shell_apk_javatests") {
   testonly = true
   java_files =
       [ "javatests/src/org/chromium/webapk/shell_apk/DexLoaderTest.java" ]
   deps = [
     ":webapk_java",
     "//base:base_java",
     "//base:base_java_test_support",
     "//chrome/android/webapk/libs/common:common_java",
     "//content/public/test/android:content_java_test_support",
   ]
   srcjar_deps = [ "javatests/dex_optimizer:dex_optimizer_service_aidl" ]
 }
 
 junit_binary("webapk_shell_apk_junit_tests") {
   java_files = [
     "junit/src/org/chromium/webapk/shell_apk/HostBrowserClassLoaderTest.java",
     "junit/src/org/chromium/webapk/shell_apk/MainActivityTest.java",
   ]
   deps = [
     ":webapk_java",
     "//chrome/android/webapk/libs/common:common_java",
   ]
 }