bookmarks: Remove a bunch of unnecessary BookmarkModelFactory::GetForProfile() calls.

bookmarks: Remove a bunch of unnecessary BookmarkModelFactory::GetForProfile() calls.

Instead of making a series of calls to it, keep the model in variable
and reuse it.

BUG=None
TEST=unit_tests --gtest_filter=BookmarkBarViewTest.*
R=sky@chromium.org

Committed: https://crrev.com/ec4bd88bad1c19db9b7c311475608a8d7a2e1718
Cr-Commit-Position: refs/heads/master@{#339740}

[sky, 2015-07-21 19:31:51]

LGTM

[tfarina, 2015-07-21 20:04:59]

The CQ bit was checked by tfarina@chromium.org

[tfarina, 2015-07-21 20:05:00]

The patchset sent to the CQ was uploaded after l-g-t-m from sky@chromium.org
Link to the patchset: https://codereview.chromium.org/1246833004/#ps20001
(title: "fix")

[commit-bot: I haz the power, 2015-07-21 20:05:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1246833004/20001

[commit-bot: I haz the power, 2015-07-21 20:36:21]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-07-21 20:38:22]

Patchset 2 (id:??) landed as
https://crrev.com/ec4bd88bad1c19db9b7c311475608a8d7a2e1718
Cr-Commit-Position: refs/heads/master@{#339740}