Enables early out on trybot linux_chromium_clang_dbg builder

I'm starting with this one to make sure everything works ok.

BUG=383609
TEST=none
TBR=iannucci@chromium.org

Review URL: https://codereview.chromium.org/385483003

git-svn-id: http://src.chromium.org/chrome/trunk/src/testing@284116 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
Update targetSdkVersion to 20.

Applications targeting this or a later release will get these new changes
in behavior:
  - AlertDialog might not have a default background if the theme does not
    specify one.

BUG=393019
TBR=stgao@chromium.org,blundell@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/402613008

git-svn-id: http://src.chromium.org/chrome/trunk/src/testing@284131 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
Mojo: Enable mojo_shell_tests on *all* (?) the Linux bots.

Apparently, I need to repeat myself 4 more times.

R=sky@chromium.org

Review URL: https://codereview.chromium.org/393353002

git-svn-id: http://src.chromium.org/chrome/trunk/src/testing@284460 4ff67af0-8c30-449e-8e8b-ad334ec8d88c