PPAPI generator: Ignore more date-only changes

PPAPI generator: Ignore more date-only changes

Previously, the generator could only ignore changes in the:
// From FILENAME.idl modified DAY MON DATE TIME YEAR.
line if it was not wrapped or wrapped in a specific place. (Note this line
would otherwise change every time you generate).

This CL makes it a little better, in that it will ignore timestamp changes
regardless of where the "modified" output is wrapped. Otherwise, the generator
wants to update a few thunk files because it's now 2015. See:
https://codereview.chromium.org/849473003/
for context.

BUG=
R=bbudge@chromium.org

Committed: https://crrev.com/cd4ea7fe9e50ba0ee0ac3f08aeb0bb21653ee00b
Cr-Commit-Position: refs/heads/master@{#311767}

[dmichael (off chromium), 2015-01-15 21:28:56]

This seems to do the right thing locally.

[bbudge, 2015-01-15 21:36:06]

LGTM Thanks!

[dmichael (off chromium), 2015-01-15 21:38:37]

The CQ bit was checked by dmichael@chromium.org

[commit-bot: I haz the power, 2015-01-15 21:39:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/849283003/1

[commit-bot: I haz the power, 2015-01-15 23:33:06]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-15 23:34:14]

Patchset 1 (id:??) landed as
https://crrev.com/cd4ea7fe9e50ba0ee0ac3f08aeb0bb21653ee00b
Cr-Commit-Position: refs/heads/master@{#311767}