Remove kSkipFrame usage.

Remove kSkipFrame usage.

Since padding is no longer sent on Encoded() callbacks, dummy callbacks
aren't required to generate padding. This skip-frame behavior can then
be removed to get rid of dummy callbacks though nothing was encoded. As
frames don't have to be generated for frames that don't have to be sent
we skip encoding frames that aren't intended to be sent either, reducing
CPU load.

BUG=
R=mflodman@webrtc.org, stefan@webrtc.org

Committed: https://crrev.com/5d0379da2cbdcce6f8494209c7ab559cd6de076e
Cr-Commit-Position: refs/heads/master@{#10181}

[pbos-webrtc, 2015-10-02 13:32:34]

PTAL, I think this should reduce CPU load on sub-HD networks (and makes the code
easier).

[stefan-webrtc, 2015-10-02 13:43:08]

lgtm

https://codereview.webrtc.org/1369923005/diff/1/webrtc/test/fake_encoder.cc
File webrtc/test/fake_encoder.cc (right):

https://codereview.webrtc.org/1369923005/diff/1/webrtc/test/fake_encoder.cc#n...
webrtc/test/fake_encoder.cc:103: if (min_stream_bits > bits_available && i > 0)
{
Optionally remove {}

[pbos-webrtc, 2015-10-02 13:43:54]

-{}

[mflodman, 2015-10-06 10:51:32]

lgtm

[pbos-webrtc, 2015-10-06 11:17:56]

rebase

[pbos-webrtc, 2015-10-06 11:46:17]

bogus default return value for ConvertFrameType

[pbos-webrtc, 2015-10-06 12:05:08]

Committed patchset #4 (id:60001) manually as
5d0379da2cbdcce6f8494209c7ab559cd6de076e (presubmit successful).

[commit-bot: I haz the power, 2015-10-06 12:05:11]

Patchset 4 (id:??) landed as
https://crrev.com/5d0379da2cbdcce6f8494209c7ab559cd6de076e
Cr-Commit-Position: refs/heads/master@{#10181}