media: Add DefaultMediaPermission.

media: Add DefaultMediaPermission.

Also pass MediaPermission to ProxyDecryptor, in preparation for triggering
user prompt from ProxyDecryptor for prefixed EME implementation.

TBR=jam@chromium.org,aa@chromium.org
BUG=446263
Committed: https://crrev.com/60b430a11d662a93795cef0fd137cb7018172ab9
Cr-Commit-Position: refs/heads/master@{#314082}

[xhwang, 2015-01-30 06:19:18]

Patchset #2 (id:20001) has been deleted

[xhwang, 2015-01-30 17:53:38]

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

[xhwang, 2015-01-30 17:53:39]

sandersd: PTAL
ddorwin: FYI

[sandersd (OOO until July 31), 2015-01-30 22:16:07]

lgtm

[xhwang, 2015-01-30 22:29:51]

xhwang@chromium.org changed reviewers:
+ aa@chromium.org, jam@chromium.org

[xhwang, 2015-01-30 22:29:52]

TBRing jam@ for content/ and aa@ for html_viewer/ changes since this change is
trivial. Let me know if you want to review it, otherwise I'll land it later
today.

[xhwang, 2015-01-30 23:04:37]

rebase only

[xhwang, 2015-02-01 04:36:08]

The CQ bit was checked by xhwang@chromium.org

[commit-bot: I haz the power, 2015-02-01 04:36:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/887873003/60001

[commit-bot: I haz the power, 2015-02-01 05:21:17]

Committed patchset #3 (id:60001)

[commit-bot: I haz the power, 2015-02-01 05:22:17]

Patchset 3 (id:??) landed as
https://crrev.com/60b430a11d662a93795cef0fd137cb7018172ab9
Cr-Commit-Position: refs/heads/master@{#314082}