Marina Ciocea 576ad5d510 Make TransformableVideoFrameInterface::GetMetadata pure virtual.
GetMetadata() has been implemented downstream and can be made pure
virtual.

Bug: chromium:1069295
Change-Id: I62a3be6106552d2d82d8c413c6f523d31626b0d8
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/175001
Commit-Queue: Marina Ciocea <marinaciocea@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31281}
2020-05-15 17:46:20 +00:00
..
2020-01-21 12:13:11 +00:00
2019-06-03 08:15:09 +00:00
2020-03-24 15:14:09 +00:00
2019-02-01 13:24:47 +00:00

How to write code in the api/ directory

Mostly, just follow the regular style guide, but:

  • Note that api/ code is not exempt from the “.h and .cc files come in pairs” rule, so if you declare something in api/path/to/foo.h, it should be defined in api/path/to/foo.cc.
  • Headers in api/ should, if possible, not #include headers outside api/. Its not always possible to avoid this, but be aware that it adds to a small mountain of technical debt that were trying to shrink.
  • .cc files in api/, on the other hand, are free to #include headers outside api/.

That is, the preferred way for api/ code to access non-api/ code is to call it from a .cc file, so that users of our API headers wont transitively #include non-public headers.

For headers in api/ that need to refer to non-public types, forward declarations are often a lesser evil than including non-public header files. The usual rules still apply, though.

.cc files in api/ should preferably be kept reasonably small. If a substantial implementation is needed, consider putting it with our non-public code, and just call it from the api/ .cc file.