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- Add extension strings
- Generate localizable.strings files for the extension
- Add translation expectations and resource ids
- Add screenshots

Bug: 1138717
Change-Id: I443a367af96cad05dfa32ab6d94ca17c1f4c9524
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2504635
Commit-Queue: Javier Flores <javierrobles@chromium.org>
Reviewed-by: Samuel Huang <huangs@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821842}