Disable a flaky content_unittest

The test is flaky on Android. More details in the bug.

BUG=339534
TBR=michaeln@chromium.org

Review URL: https://codereview.chromium.org/150683003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248725 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248725
[GFX] Add hostname elider. Add ability to elide strings at the beginning.

R=xji@chromium.org

Review URL: https://codereview.chromium.org/144513002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248726 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248726