Tweak some DVLOGs in media code.

Tweak some DVLOGs in media code.

As a follow up to 792fb3d, brings VideoRendererImpl in
line with AudioRendererImpl and also increases the DVLOG
level for the high-frequency CurrentMediaTime() function.

TBR=xhwang

Committed: https://crrev.com/a62dfabc6e36a91cdea6d59b4a1c4465752c5d76
Cr-Commit-Position: refs/heads/master@{#293087}

[scherkus (not reviewing), 2014-09-03 03:37:06]

scherkus@chromium.org changed reviewers:
+ xhwang@chromium.org

[scherkus (not reviewing), 2014-09-03 03:37:49]

The CQ bit was checked by scherkus@chromium.org

[commit-bot: I haz the power, 2014-09-03 03:39:08]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/scherkus@chromium.org/529333002/1

[xhwang, 2014-09-03 05:06:36]

lgtm

[commit-bot: I haz the power, 2014-09-03 06:47:42]

Committed patchset #1 (id:1) as 6df9185e766c625f019471234089b62ede362b4d

[commit-bot: I haz the power, 2014-09-10 03:24:06]

Patchset 1 (id:??) landed as
https://crrev.com/a62dfabc6e36a91cdea6d59b4a1c4465752c5d76
Cr-Commit-Position: refs/heads/master@{#293087}