Files.app: Analytics tweaks

Files.app: Analytics tweaks

1) Report total errors while reporting import task statistics.
2) Report addView when volume changes.
3) Send hit when history file changes.

BUG=420680
TEST=browser_test: FileManagerJsTest.*

Committed: https://crrev.com/2df221e4be8e76b2c0b9ba4db79eb358605430ff
Cr-Commit-Position: refs/heads/master@{#317076}

[Steve McKay, 2015-02-19 02:02:23]

smckay@chromium.org changed reviewers:
+ kenobi@chromium.org, mtomasz@chromium.org

[mtomasz, 2015-02-19 02:49:26]

CL title missing. lgtm.

[Steve McKay, 2015-02-19 14:59:54]

Ben. I'll be traveling today. Please feel free to flip the commit bit if you're
happy (enough) with the CL.

[Ben Kwa, 2015-02-19 17:43:22]

The CQ bit was checked by kenobi@chromium.org

[Ben Kwa, 2015-02-19 17:43:23]

lgtm

[commit-bot: I haz the power, 2015-02-19 17:44:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/933553003/20001

[commit-bot: I haz the power, 2015-02-19 18:07:23]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-19 18:08:01]

Patchset 2 (id:??) landed as
https://crrev.com/2df221e4be8e76b2c0b9ba4db79eb358605430ff
Cr-Commit-Position: refs/heads/master@{#317076}