args.gn:
target_os = "android"
enable_chrome_android_internal = false
use_goma = true
enable_incremental_javac = true
disable_incremental_isolated_processes = true

building chrome_public_apk_incremental:
nice ninja -C out/AndroidDebug -j2000 -l20 chrome_public_apk_incremental && out/AndroidDebug/bin/install_chrome_public_apk_incremental

Appears to build & install fine but on starting the app it crashes with:

06-05 12:38:30.513 E/AndroidRuntime(10407): FATAL EXCEPTION: main
06-05 12:38:30.513 E/AndroidRuntime(10407): Process: org.chromium.chrome, PID: 10407
06-05 12:38:30.513 E/AndroidRuntime(10407): java.lang.RuntimeException: Unable to instantiate application org.chromium.incrementali
nstall.BootstrapApplication: java.lang.RuntimeException: Incremental install failed.
06-05 12:38:30.513 E/AndroidRuntime(10407):     at android.app.LoadedApk.makeApplication(LoadedApk.java:948)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5765)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at android.app.ActivityThread.-wrap1(Unknown Source:0)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1661)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at android.os.Handler.dispatchMessage(Handler.java:105)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at android.os.Looper.loop(Looper.java:164)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at android.app.ActivityThread.main(ActivityThread.java:6541)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at java.lang.reflect.Method.invoke(Native Method)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
06-05 12:38:30.513 E/AndroidRuntime(10407): Caused by: java.lang.RuntimeException: Incremental install failed.
06-05 12:38:30.513 E/AndroidRuntime(10407):     at org.chromium.incrementalinstall.BootstrapApplication.attachBaseContext(Bootstrap
Application.java:149)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at android.app.Application.attach(Application.java:189)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at android.app.Instrumentation.newApplication(Instrumentation.java:1102)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at android.app.Instrumentation.newApplication(Instrumentation.java:1086)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at android.app.LoadedApk.makeApplication(LoadedApk.java:942)
06-05 12:38:30.513 E/AndroidRuntime(10407):     ... 9 more
06-05 12:38:30.513 E/AndroidRuntime(10407): Caused by: java.lang.ArrayStoreException: source[0] of type dalvik.system.DexPathList$E
lement cannot be stored in destination array of type dalvik.system.DexPathList$NativeLibraryElement[]
06-05 12:38:30.513 E/AndroidRuntime(10407):     at java.lang.System.arraycopy(Native Method)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at org.chromium.incrementalinstall.Reflect.concatArrays(Reflect.java:52)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at org.chromium.incrementalinstall.ClassLoaderPatcher.addNativeLibrarySearchPath(Cl
assLoaderPatcher.java:175)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at org.chromium.incrementalinstall.ClassLoaderPatcher.importNativeLibs(ClassLoaderP
atcher.java:147)
06-05 12:38:30.513 E/AndroidRuntime(10407):     at org.chromium.incrementalinstall.BootstrapApplication.attachBaseContext(Bootstrap
Application.java:101)
06-05 12:38:30.513 E/AndroidRuntime(10407):     ... 13 more

Looks like https://bugs.chromium.org/p/chromium/issues/detail?id=682814 again - maybe the fix needs tweaking?

(I also tried with 'use_unpublished_apis = true' in gn args but got the same problem)