Let PDFium handle event when there is not yet a visible page.

Let PDFium handle event when there is not yet a visible page.

Speculative fix for 415307. CF will confirm.
The stack trace for that bug indicates an attempt to index by -1, which is consistent with no visible page.

BUG=415307
Committed: https://crrev.com/9b04ffd8e7a07e9b2947fe5b71acf85dff38a63f
Cr-Commit-Position: refs/heads/master@{#295421}

[Tom Sepez, 2014-09-17 23:56:11]

tsepez@chromium.org changed reviewers:
+ gene@chromium.org

[Tom Sepez, 2014-09-17 23:56:50]

@gene - please review. Thanks.

[gene, 2014-09-18 01:44:45]

lgtm

[Tom Sepez, 2014-09-18 05:02:58]

The CQ bit was checked by tsepez@chromium.org

[commit-bot: I haz the power, 2014-09-18 05:04:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/560133004/1

[commit-bot: I haz the power, 2014-09-18 05:36:06]

Committed patchset #1 (id:1) as ebfb5b5746da7a3a8d7098b1709ec52ae7df0e11

[commit-bot: I haz the power, 2014-09-18 05:37:11]

Patchset 1 (id:??) landed as
https://crrev.com/9b04ffd8e7a07e9b2947fe5b71acf85dff38a63f
Cr-Commit-Position: refs/heads/master@{#295421}