power: Add preferred_minimum_external_power to PowerSupplyProperties.

Provide clients with the value of the preferred minimum external power
input so it can be exposed to the user when warning about low power

TEST=unit tests

Change-Id: I27825fc50ecfb7c45db201a8c2856f26bc0721db
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform2/+/2404983
Tested-by: Sam McNally <sammc@chromium.org>
Reviewed-by: Puthikorn Voravootivat <puthik@chromium.org>
Commit-Queue: Sam McNally <sammc@chromium.org>
Cr-Mirrored-From: https://chromium.googlesource.com/chromiumos/platform2
Cr-Mirrored-Commit: 6786ac63afd04a8568314a22f1194d38661619a9
1 file changed
tree: 4804f3dee488178f32784978c5d2b89d776ede96
  1. .gitignore
  2. BUILD.gn
  3. Cargo.toml
  6. README.md
  7. build.rs
  8. constants/
  9. dbus/
  10. src/
  11. switches/
  12. system_api.pc

This directory (platform2/system_api) contains constants and definitions like D-Bus service names that are shared between Chromium and Chromium OS.

This directory is only for things like headers and .proto files. No implementation should be added.

When writting a .proto file make sure to use:

option optimize_for = LITE_RUNTIME;

This will force usage of a lite protobuf instead of a full/heavy weight protobuf. The browser only links against the light version, so you will get cryptic link errors about missing parts of Message if you define a protobuf here and then try to use it in Chrome. Currently CrOS links against the full protobuffer library, but that might change in the future.

When declaring a protobuf, avoid use of required unless it is exactly what you mean. “Required is Forever” and very rarely should actually be used. Consult Protocol Buffer Basics: C++ for a detailed of this issue.