On Win8.1 and Win10 when the window is occluded the cropping capturer
falls back to the PrintWindow API. But without a special flag it
fails when trying to capture apps that are using DirectComposition.
So just pass this undocumented flag named PW_RENDERFULLCONTENT to fix
the fallback case of the cropping capturer.
Due to new app framing on Win8 and Win10 the shadow of the window
are captured as black like if for the maximize case on Win7. So
just use the utility function webrtc::GetCroppedWindowRect and
remove the local GetWindowDrawableRect helper. The former returns
the same result as the later on Win7 so no real change is made here,
just that we make the WindowCapturerWin compatible with newer Windows.
Bug: webrtc:10734
Change-Id: Idb793ca0691261042569c30410669c4a5ad0c8ec
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/144960
Commit-Queue: Julien Isorce <julien.isorce@chromium.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28570}