Renamed all the *_metro_1x.png theme art assets to the more generic *_touch_1x.png and moved them from chrome/app/theme/metro to chrome/app/theme/touch

I need this as ground-work for touch-friendly toolbar.

BUG=125265
TEST=compiles
TBR=sky@chromium.org

Review URL: https://chromiumcodereview.appspot.com/10264032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@134728 0039d316-1c4b-4281-b951-d872f2087c98