NaCl: Clean up some uses of native_client/src/trusted/desc/

NaCl: Clean up some uses of native_client/src/trusted/desc/

Switch to using the definitions from src/public/ where possible.

Change DEPS to remove blanket allowances of src/trusted/desc/, and
only whitelist some remaining required headers.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=2832
TEST=build

Committed: https://crrev.com/a3f1ea0157af7cae0e6bb171f3926304797a0b37
Cr-Commit-Position: refs/heads/master@{#333057}

[Mark Seaborn, 2015-06-05 13:48:47]

mseaborn@chromium.org changed reviewers:
+ jvoung@chromium.org

[jvoung (off chromium), 2015-06-05 15:49:38]

lgtm

[Mark Seaborn, 2015-06-05 15:50:44]

The CQ bit was checked by mseaborn@chromium.org

[commit-bot: I haz the power, 2015-06-05 15:51:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1171493003/20001

[commit-bot: I haz the power, 2015-06-05 15:55:42]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-06-05 15:56:31]

Patchset 2 (id:??) landed as
https://crrev.com/a3f1ea0157af7cae0e6bb171f3926304797a0b37
Cr-Commit-Position: refs/heads/master@{#333057}