RELAND2: MediaRecorder: only announce h264/avc1 support if RTC_USE_H264

The relanded CL got reverted as well (!) because it still broke
media_capabilities/encodingInfo.html; this CL splits the avc1/h264
parts in a file on its own, and rewrites all of those tests to not
use generate_tests (see comment in crrev.com/c/1393538). Only the
-avc1.html tests are marked as [Pass Failure] in TestExpectations.

Original 2nd CL description --------------------------------------------

The original CL got reverted because:
- It broke media_capabilities/encodingInfo.html
- It broke the MediaRecorder LayoutTests on non-Android bots
when RTC_USE_H264 is not defined (which is pretty pervasive, it turns
out). This CL then adds the necessary TestExceptions.

Original CL description ------------------------------------------------
Support for AVC1 encoding (a.k.a. H264) is dependent on RTC_USE_H264 [1],
but due to an omission, this was not tested when enumerating the video
codecs. This CL fixes that.

[1] https://cs.chromium.org/chromium/src/third_party/webrtc/webrtc.gni?type=cs&q=rtc_use_h264&sq=package:chromium&g=0&l=156

Bug: 809980, 719023
Change-Id: I865e9007ffce810998f62d1e187bf4ecf499badd
Reviewed-on: https://chromium-review.googlesource.com/c/1395887
Commit-Queue: Miguel Casas <mcasas@chromium.org>
Reviewed-by: Miguel Casas <mcasas@chromium.org>
Cr-Original-Original-Commit-Position: refs/heads/master@{#620078}
Reviewed-on: https://chromium-review.googlesource.com/c/1396452
Cr-Original-Commit-Position: refs/heads/master@{#620453}
Reviewed-on: https://chromium-review.googlesource.com/c/1399823
Reviewed-by: Emircan Uysaler <emircan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#621142}
7 files changed