Revert "Reland "Android: Allow proguard to strip unused native methods.""

This reverts commit 1a055a9b.

Reason for revert: broken tree:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/android-rel/4386

Original change's description:
> Reland "Android: Allow proguard to strip unused native methods."
> 
> Reland of dc8f3c0a.
> 
> chrome_public_test_apk is now merged with chrome_public_apk_for_test
> which should fix the proguard issue.
> 
> TBR: agrieve@chromium.org
> Bug: 688465
> Change-Id: Ie43eae7f945e5ae444f1cb0adc0703b334402f3c
> Reviewed-on: https://chromium-review.googlesource.com/c/1333988
> Reviewed-by: Eric Stevenson <estevenson@chromium.org>
> Commit-Queue: Eric Stevenson <estevenson@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#608038}

TBR=estevenson@chromium.org

Change-Id: Ia718741dad550c0a4c861bd634a21232518dd161
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 688465
Reviewed-on: https://chromium-review.googlesource.com/c/1336064Reviewed-by: Roger Tawa <rogerta@chromium.org>
Commit-Queue: Roger Tawa <rogerta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608074}

base/android/proguard/chromium_code.flags

@@ -38,6 +38,9 @@
 -keepclasseswithmembers class * {
   @org.chromium.base.annotations.UsedByReflection <fields>;
 }
+-keepclasseswithmembers,includedescriptorclasses class * {
+  native <methods>;
+}
 
 # Remove methods annotated with this if their return value is unused.
 -assumenosideeffects class ** {

base/android/proguard/explicit_jni_registration.flags

-# Copyright 2018 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.
-
-# -keepclasseswithmembers rather than -keepclasseswithmembernames to avoid
-# shrinking of unused native methods. Explicit JNI registration requires even
-# unused classes to be present during RegisterNatives().
--keepclasseswithmembers,includedescriptorclasses class * {
-  native <methods>;
-}

base/android/proguard/implicit_jni_registration.flags

-# Copyright 2018 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.
-
-# -keepclasseswithmembernames rather than -keepclasseswithmembers to allow
-# shrinking of unused native methods.
--keepclasseswithmembernames,includedescriptorclasses class * {
-  native <methods>;
-}

build/config/android/rules.gni

@@ -2433,13 +2433,6 @@ if (enable_java_templates) {
           proguard_configs += [ "//build/android/multidex.flags" ]
         }
         proguard_mapping_path = _proguard_mapping_path
-        if (_use_chromium_linker) {
-          proguard_configs +=
-              [ "//base/android/proguard/explicit_jni_registration.flags" ]
-        } else {
-          proguard_configs +=
-              [ "//base/android/proguard/implicit_jni_registration.flags" ]
-        }
       }
 
       # Don't depend on the runtime_deps target in order to avoid having to

components/cronet/android/BUILD.gn

@@ -470,7 +470,6 @@ action("cronet_combine_proguard_flags") {
   script = "//components/cronet/tools/generate_proguard_file.py"
   sources = [
     "//base/android/proguard/chromium_code.flags",
-    "//base/android/proguard/explicit_jni_registration.flags",
     "//components/cronet/android/cronet_impl_native_proguard.cfg",
   ]
   outputs = [