Reason for revert: Fix bug introduced by keeping the allocated decoders in a map. Original issue's description: > Revert of Prepare for injectable SW decoders (patchset #3 id:40001 of https://codereview.webrtc.org/3009973002/ ) > > Reason for revert: > Tentative revert since it seems to cause problems in Chrome, MAC. > > https://build.chromium.org/p/chromium.webrtc.fyi/builders/Mac%20Tester/builds/42684 > > > > Original issue's description: > > Prepare for injectable SW decoders > > > > Pretty much mirrors the work done on the encoding side in CLs: > > > > "Clean up ownership of webrtc::VideoEncoder" > > https://codereview.webrtc.org/3007643002/ > > > > "Let VideoEncoderSoftwareFallbackWrapper own the wrapped encoder" > > https://codereview.webrtc.org/3007683002/ > > > > "WebRtcVideoEngine: Encapsulate logic for unifying internal and external video codecs" > > https://codereview.webrtc.org/3006713002/ > > > > BUG=webrtc:7925 > > > > Review-Url: https://codereview.webrtc.org/3009973002 > > Cr-Commit-Position: refs/heads/master@{#19641} > > Committed:084c55a63a> > TBR=magjed@webrtc.org,andersc@webrtc.org > # Not skipping CQ checks because original CL landed more than 1 days ago. > BUG=webrtc:7925 > > Review-Url: https://codereview.webrtc.org/3010953002 > Cr-Commit-Position: refs/heads/master@{#19647} > Committed:1f88531038TBR=magjed@webrtc.org,perkj@webrtc.org # Not skipping CQ checks because original CL landed more than 1 days ago. BUG=webrtc:7925 Review-Url: https://codereview.webrtc.org/3005363002 Cr-Commit-Position: refs/heads/master@{#19782}