Revert "Enable the browser side thumbnailing on Chrome OS."
Revert "Enable the browser side thumbnailing on Chrome OS."

This reverts commit c00a617305d2a43f55e129da7ebe0f5c9312cb27

Change-Id: I71918b62a426df19fc0577f07a4c4ec09fa869be
Reviewed-on: https://gerrit.chromium.org/gerrit/19129
Commit-Ready: Emmanuel R. Saint-Loubert-Bie <ff7e642d60481cb403a503ef875e432aea9151d8@chromium.org>
Reviewed-by: Emmanuel R. Saint-Loubert-Bie <ff7e642d60481cb403a503ef875e432aea9151d8@chromium.org>
Tested-by: Emmanuel R. Saint-Loubert-Bie <ff7e642d60481cb403a503ef875e432aea9151d8@chromium.org>

chadversary/chromiumos.platform.login_manager,chadversary/chromiumos.platform.login_manager,chadversary/chromiumos.platform.login_manager