Separate the JNI function that controls logging levels into two.

The parameters for Logging.enableTracing() were creating the impression
that they control level and severity of one tracing system and they are
meant to be used together. In fact the "levels" parameter controlled one
tracing system (WEBRTC_TRACE), and the "severity" parameter was
responsible for a completely different one: setting the severity level
above which log messages from LOG() will be directed to the
platform-specific debug output (logcat on Android).

The method signature suggested that the "path" parameter applied to both
systems - while it was only meaningful for the WEBRTC_TRACE; LOG
messages were directed to ADB logcat no matter what the Path value was.
It is possible to redirect LOG messages to a file, but that is done
using a completely different set of APIs
 - PeerConnectionFactory.startInternalTracingCapture().

I've separated these two methods to make it more clear which of the
parameters controls which system.

NOTRY=true

Review-Url: https://codereview.webrtc.org/2110853003
Cr-Original-Commit-Position: refs/heads/master@{#13334}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 4c4cb5b98456cb16d9174485bd59e58a861fd0f5
3 files changed