GitLab

This reverts commit 09f15bdb.

Reason for revert: http://crbug.com/918796

Original change's description:
> Android: Turning on R8 instead of Proguard for public targets
> 
> We are in the process of migrating to R8 to replace Proguard. This is
> the first step - move all usages of Proguard in public targets to R8.
> 
> Some refactorings were natural with the few forced changes this caused.
> 
> TBR=smaier
> 
> Bug: 908988, 913554
> Change-Id: I2139919598fba1643d7560dc5557d5efb9a5887c
> Reviewed-on: https://chromium-review.googlesource.com/c/1357306
> Reviewed-by: Sam Maier <smaier@chromium.org>
> Reviewed-by: agrieve <agrieve@chromium.org>
> Commit-Queue: Sam Maier <smaier@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#619471}

TBR=wnwen@chromium.org,agrieve@chromium.org,smaier@chromium.org

Change-Id: Ieb34a24da7c001e78d832f7300855c7c7c749add
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 908988, 913554
Reviewed-on: https://chromium-review.googlesource.com/c/1394528Reviewed-by: Egor Pasko <pasko@chromium.org>
Commit-Queue: Egor Pasko <pasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#619634}