Fix a crash that proguard truncates the package name of gifplayer

Fix a crash that proguard truncates the package name of gifplayer

An animated doodle crash has been observed on release builds because
gifplayer's package name is truncated by proguard. This CL does a quick
fix for that.

BUG=537066
Committed: https://crrev.com/8899e6679c8d9ce3bf6b719981e476c9fb8089e1
Cr-Commit-Position: refs/heads/master@{#351451}

[Ian Wen, 2015-09-29 19:22:38]

ianwen@chromium.org changed reviewers:
+ aurimas@chromium.org, kerz@chromium.org, newt@chromium.org

[Ian Wen, 2015-09-29 19:22:38]

kerz@ this is a quick fix that solves the crash and it should be landed on the
special branch.

newt@ this CL is a quick hack and I do not recommend us land it on trunk. I will
figure out why a newly created proguard.flags does not work in gif_player.gyp
later.

[kerz_chromium, 2015-09-29 19:56:58]

lgtm

[Ian Wen, 2015-09-29 22:05:02]

newt@: ptal the second patchset.

kerz@: both patchset is eligible to be merged to the dev branch.

[newt (away), 2015-09-29 23:27:15]

patch set 2 lgtm

[Ian Wen, 2015-09-29 23:27:39]

The CQ bit was checked by ianwen@chromium.org

[Ian Wen, 2015-09-29 23:27:40]

The patchset sent to the CQ was uploaded after l-g-t-m from kerz@chromium.org
Link to the patchset: https://codereview.chromium.org/1370363003/#ps20001
(title: "a more correct less hacky approach")

[commit-bot: I haz the power, 2015-09-29 23:28:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1370363003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1370363003/20001

[Ian Wen, 2015-09-29 23:29:25]

An instrumentation test will be on its way. The crash like today's should have
been caught by a test, however simple it is.

[commit-bot: I haz the power, 2015-09-30 00:33:02]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-30 00:33:51]

Patchset 2 (id:??) landed as
https://crrev.com/8899e6679c8d9ce3bf6b719981e476c9fb8089e1
Cr-Commit-Position: refs/heads/master@{#351451}