In-class-initialize LIMITED_MEDIA_LOG log counters
Per previous code review comment [1]
this change updates callers of LIMITED_MEDIA_LOG to use in-class
initialization of the log counters. Opportunistic fixes to in-class
initialize (for simple values) other members are included for the
classes that use LIMITED_MEDIA_LOG.
[1]
https://codereview.chromium.org/
1281113002/diff/80001/media/filters/source_buffer_stream.cc#newcode214
TEST=no regression
Review URL: https://codereview.chromium.org/
1278193003
Cr-Commit-Position: refs/heads/master@{#343978}