Mojo: Minor core.h reorganization.

Move time ticks stuff to be first. I'm trying to keep things in order
starting from simplest/most essential.

R=sky@chromium.org

Review URL: https://codereview.chromium.org/101513005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240223 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240223
Update UI assets for screen capture and screen sharing.

Remove the "IDR_AURA_UBER_TRAY_DISPLAY_LIGHT" icons because they are no longer used anywhere.

BUG=327821
TEST=verified on device that the correct assets are used: screen capture/sharing uses the screenshare icons, and extended display uses the multi-display status icons.
R=oshima@chromium.org

Review URL: https://codereview.chromium.org/113423003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240224 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240224