Android: Make R8 not require ",allowaccessmodification"

via a custom patch to it that causes it to consider all
-keep rules to have implicit ",allowaccessmodification".

Causes many more downstream play services methods to be
removed.

Change-Id: I9532fe9621d9a011202a1b9044cb3467ae207a18
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2223651
Auto-Submit: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Sam Maier <smaier@chromium.org>
Reviewed-by: Zhongyi Shi <zhongyi@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#773790}

DEPS

@@ -1323,7 +1323,7 @@ deps = {
       'packages': [
           {
               'package': 'chromium/third_party/r8',
-              'version': 'bri3RbTe5EACoEqrT7RBNXf6QZ1fIHWpsWpg9lW-JEQC',
+              'version': 'gobCh01BNwJNyLHHNFUmLWSMaAbe4x3izuzBFzxQpDoC',
           },
       ],
       'condition': 'checkout_android',

base/android/proguard/chromium_apk.flags

@@ -77,6 +77,6 @@
 }
 
 # Protobuf java lite runtime uses reflection
--keepclassmembers,allowaccessmodification class * extends com.google.protobuf.GeneratedMessageLite {
+-keepclassmembers class * extends com.google.protobuf.GeneratedMessageLite {
   <fields>;
 }

base/android/proguard/chromium_code.flags

@@ -34,13 +34,13 @@
 -keep @org.chromium.base.annotations.UsedByReflection class ** {}
 
 # Keeps for method level annotations.
--keepclasseswithmembers,allowaccessmodification class ** {
+-keepclasseswithmembers class ** {
   @org.chromium.base.annotations.AccessedByNative <fields>;
 }
--keepclasseswithmembers,includedescriptorclasses,allowaccessmodification class ** {
+-keepclasseswithmembers,includedescriptorclasses class ** {
   @org.chromium.base.annotations.CalledByNative <methods>;
 }
--keepclasseswithmembers,includedescriptorclasses,allowaccessmodification class ** {
+-keepclasseswithmembers,includedescriptorclasses class ** {
   @org.chromium.base.annotations.CalledByNativeUnchecked <methods>;
 }
 -keepclasseswithmembers class ** {

chrome/android/java/monochrome_public_bundle.proguard_flags.expected

@@ -155,7 +155,7 @@
 }
 
 # Protobuf java lite runtime uses reflection
--keepclassmembers,allowaccessmodification class * extends com.google.protobuf.GeneratedMessageLite {
+-keepclassmembers class * extends com.google.protobuf.GeneratedMessageLite {
   <fields>;
 }
 
@@ -198,13 +198,13 @@
 -keep @org.chromium.base.annotations.UsedByReflection class ** {}
 
 # Keeps for method level annotations.
--keepclasseswithmembers,allowaccessmodification class ** {
+-keepclasseswithmembers class ** {
   @org.chromium.base.annotations.AccessedByNative <fields>;
 }
--keepclasseswithmembers,includedescriptorclasses,allowaccessmodification class ** {
+-keepclasseswithmembers,includedescriptorclasses class ** {
   @org.chromium.base.annotations.CalledByNative <methods>;
 }
--keepclasseswithmembers,includedescriptorclasses,allowaccessmodification class ** {
+-keepclasseswithmembers,includedescriptorclasses class ** {
   @org.chromium.base.annotations.CalledByNativeUnchecked <methods>;
 }
 -keepclasseswithmembers class ** {

components/cronet/android/BUILD.gn

@@ -482,7 +482,6 @@ action("cronet_combine_proguard_flags") {
 
     # Massage the proguard rules to work with AppReduce.
     "//components/cronet/android/cronet_appreduce_workaround.patch",
-    "//components/cronet/android/cronet_appreduce_workaround2.patch",
     "//components/cronet/android/cronet_impl_native_proguard.cfg",
   ]
   outputs = [ "$target_gen_dir/cronet_impl_native_proguard.cfg" ]

components/cronet/android/cronet_appreduce_workaround2.patch

-This patch works as a supplement for cronet_appreduce_workaround.patch.
-See crbug.com/1087646 on why this is needed.
-For more information, also see cronet_appreduce_workaround.patch.
-
---- base/android/proguard/chromium_code.flags	2020-05-29 11:34:48.748109273 -0700
-+++ modified.flags	2020-05-29 12:20:30.692111915 -0700
-@@ -34,13 +34,13 @@
- -keep @org.chromium.base.annotations.UsedByReflection class ** {}
- 
- # Keeps for method level annotations.
---keepclasseswithmembers,allowaccessmodification class ** {
-+-keepclasseswithmembers class ** {
-   @org.chromium.base.annotations.AccessedByNative <fields>;
- }
---keepclasseswithmembers,includedescriptorclasses,allowaccessmodification class ** {
-+-keepclasseswithmembers,includedescriptorclasses class ** {
-   @org.chromium.base.annotations.CalledByNative <methods>;
- }
---keepclasseswithmembers,includedescriptorclasses,allowaccessmodification class ** {
-+-keepclasseswithmembers,includedescriptorclasses class ** {
-   @org.chromium.base.annotations.CalledByNativeUnchecked <methods>;
- }
- -keepclasseswithmembers class ** {

third_party/r8/README.chromium

@@ -18,7 +18,6 @@ desugar_jdk_libs.json
 R8 is a proguard-like optimizer that also has the ability to dex.
 
 Local Modifications:
-* Cherry-picked R8 commit: b8464335ec1e587bde88d7a12c90d59531be10de
 * Refer to commit descriptions within "patches" directory.
 * Added "playground" directory for quick "how does this optimize" tests.
 
@@ -27,7 +26,7 @@ Update Instructions:
 git clone https://r8.googlesource.com/r8
 cd r8
 # Apply patches:
-git am $CHROMIUM_SRC/third_party/r8/patches *.patch
+git am $CHROMIUM_SRC/third_party/r8/patches/*.patch
 # Build:
 tools/gradle.py r8
 # Shrink (improves r8/d8 launch time):

third_party/r8/patches/0007-Allow-access-modification-everywhere.patch

+From 69f75c5fa4d5dd8607ec54df94b9c48d68dd5422 Mon Sep 17 00:00:00 2001
+From: Andrew Grieve <agrieve@chromium.org>
+Date: Sun, 31 May 2020 22:09:27 -0400
+Subject: [PATCH] Allow access modification everywhere
+
+Chrome does not need need -keep to maintain original visibility.
+Loosening this constraint allows for better optimization, and is easier
+than adding ",allowaccessmodification" to every single -keep rule.
+---
+ .../java/com/android/tools/r8/shaking/AppInfoWithLiveness.java  | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/main/java/com/android/tools/r8/shaking/AppInfoWithLiveness.java b/src/main/java/com/android/tools/r8/shaking/AppInfoWithLiveness.java
+index 275b882fc..be214ad60 100644
+--- a/src/main/java/com/android/tools/r8/shaking/AppInfoWithLiveness.java
++++ b/src/main/java/com/android/tools/r8/shaking/AppInfoWithLiveness.java
+@@ -927,7 +927,7 @@ public class AppInfoWithLiveness extends AppInfoWithClassHierarchy
+ 
+   public boolean isAccessModificationAllowed(DexReference reference) {
+     assert options().getProguardConfiguration().isAccessModificationAllowed();
+-    return allowAccessModification.contains(reference) || !isPinned(reference);
++    return true;
+   }
+ 
+   public boolean isPinned(DexReference reference) {
+-- 
+2.27.0.rc0.183.gde8f92d652-goog
+