BASELINE: Update Chromium to 68.0.3440.125

Change-Id: I23f19369e01f688e496f5bf179abb521ad73874f
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

1 files changed, 30 insertions, 0 deletions

diff --git a/chromium/media/README.md b/chromium/media/README.md
index 33d71df3799..71ad42ffb92 100644
--- a/chromium/media/README.md
+++ b/chromium/media/README.md
@@ -151,3 +151,33 @@ issues, it's helpful to review the internal logs at chrome://media-internals.
 The internals page contains information about active
 `media::WebMediaPlayerImpl`, `media::AudioInputController`,
 `media::AudioOutputController`, and `media::AudioOutputStream` instances.
+
+
+
+# Logging
+
+Media playback typically involves multiple threads, in many cases even multiple
+processes. Media operations are often asynchronous running in a sandbox. These
+make attaching a debugger (e.g. GDB) sometimes less efficient than other
+mechanisms like logging.
+
+## DVLOG
+
+In media we use DVLOG() a lot. It makes filename-based filtering super easy.
+Within one file, not all logs are created equal. To make log filtering
+more convenient, use appropriate log levels. Here are some general
+recommendations:
+
+* DVLOG(1): Once per playback events or other important events, e.g.
+  construction/destruction, initialization, playback start/end, suspend/resume,
+  any error conditions.
+* DVLOG(2): Recurring events per playback, e.g. seek/reset/flush, config change.
+* DVLOG(3): Frequent events, e.g. demuxer read, audio/video buffer decrypt or
+  decode, audio/video frame rendering.
+
+## MediaLog
+
+MediaLog will send logs to `about://media-internals`, which is easily accessible
+by developers (including web developes), testers and even users to get detailed
+information about a playback instance. For guidance on how to use MediaLog, see
+`media/base/media_log.h`.
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