A few notes on rules that I think should be tweaked:

-keep class * implements org.chromium.base.test.params.ParameterProvider
* Should not be there for non-test apks.
* Should have {}s

-keep class org.chromium.content.app.SandboxedProcessService
* Should add {}s and explicitly list <init> to keep.

-optimizations !class/merging/horizontal
* Remove once we move to r8.

There are also some rules from android_arch_lifecycle_runtime_java that seem overly broad and perhaps unnecessary:

  1655 ################################################################################
  1656 -keepattributes *Annotation*
  1657 
  1658 -keepclassmembers enum android.arch.lifecycle.Lifecycle$Event {
  1659     <fields>;
  1660 }
  1661 
  1662 -keep class * implements android.arch.lifecycle.LifecycleObserver {
  1663 }
  1664 
  1665 -keep class * implements android.arch.lifecycle.GenericLifecycleObserver {
  1666     <init>(...);
  1667 }
  1668 
  1669 -keepclassmembers class ** {
  1670     @android.arch.lifecycle.OnLifecycleEvent *;
  1671 }


We should try to disable them by adding an "ignore_proguard = true" here:
https://cs.chromium.org/chromium/src/build/config/android/rules.gni?rcl=dec72e86b3c1d8dd4de2bb033fc551cc25b63ce8&l=3510