Disable BrowserPluginHostTest.ReloadEmbedder test.

This test is flaky on multiple bots. See bug.

TBR=danakj@chromium.org
BUG=339904

Review URL: https://codereview.chromium.org/133793010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248258 0039d316-1c4b-4281-b951-d872f2087c98
[Sync] Remove bookmark model observer on DTC abort

If the bookmark datatype controller gets aborted, but the bookmark model
then finishes loading, we crash due to resetting the model load callback
upon abort. At abort time, we should instead unregister from all model
callbacks.

BUG=333948

Review URL: https://codereview.chromium.org/138543009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248259 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248259