Fix UMA recoding code for FileBrowser.ViewingFileType.

Fix UMA recoding code for FileBrowser.ViewingFileType.

In r239446 I carelessly inserted '.ico' to the array but
I should have not. The array is for indexing enum of metric
stat that need to match with remote side config.

Let me just revert the addition. I think we are not so eager
to count '.ico''s popularity.

BUG=339023
R=hirono@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=247826

[hirono, 2014-01-29 10:33:31]

lgtm!

[commit-bot: I haz the power, 2014-01-29 10:56:27]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kinaba@chromium.org/130803008/1

[commit-bot: I haz the power, 2014-01-30 01:49:33]

Retried try job too often on android_aosp for step(s) compile
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=android_ao...

[commit-bot: I haz the power, 2014-01-30 03:05:27]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kinaba@chromium.org/130803008/1

[kinaba, 2014-01-30 04:02:38]

Committed patchset #1 manually as r247826 (presubmit successful).

[commit-bot: I haz the power, 2014-01-30 04:03:13]

CQ bit was unchecked on CL. Ignoring.