Revert of Unit test for sync online wallpaper

Revert of Unit test for sync online wallpaper (patchset #3 id:40001 of https://codereview.chromium.org/618743003/)

Reason for revert:
WallpaperManagerJsTest.EventPageTest not passing on Linux ChromiumOS Tests (1)
link: http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%281%29/builds/49851
errors like

[7412:7412:0930/164710:INFO:CONSOLE(179)] "Failure in test testSyncOnlineWallpaper
ReferenceError: Constants is not defined", source:  (179)
[7412:7412:0930/164710:INFO:CONSOLE(180)] "ReferenceError: Constants is not defined
    at testSyncOnlineWallpaper (file:///tmp/run_tha_teste4P5jV/chrome/test/data/chromeos/wallpaper_manager/unit_tests/event_page_unittest.js:24:11)
    at continueTesting (\u003Canonymous>:177:19)
    at runTests (\u003Canonymous>:153:5)
    at \u003Canonymous>:1:51", source:  (180)
../../chrome/browser/chromeos/extensions/wallpaper_manager_browsertest.cc:89: Failure
Value of: ExecuteWebUIResourceTest(web_contents, empty_libraries)
  Actual: false
Expected: true

Original issue's description:
> Unit test for sync online wallpaper
>
> BUG=416130
>
> Committed: https://crrev.com/9c99a1d7cd522e23f1232e53a181c9b21bda2216
> Cr-Commit-Position: refs/heads/master@{#297542}

TBR=kevers@chromium.org,bshe@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=416130
Committed: https://crrev.com/781c55e7805abe5882179d894ac1dea7575f0530
Cr-Commit-Position: refs/heads/master@{#297602}

[tapted, 2014-10-01 06:56:42]

Created Revert of Unit test for sync online wallpaper

[commit-bot: I haz the power, 2014-10-01 06:57:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/621693002/1

[commit-bot: I haz the power, 2014-10-01 06:57:57]

Committed patchset #1 (id:1) as ef0cf8d0833a2c6369ddae769b57da56d0ffd0d4

[commit-bot: I haz the power, 2014-10-01 06:58:53]

Patchset 1 (id:??) landed as
https://crrev.com/781c55e7805abe5882179d894ac1dea7575f0530
Cr-Commit-Position: refs/heads/master@{#297602}