Load the resources for max scale factor first.
- made SCALE_FACTOR_NONE != SCALE_FACTOR_100P
- updated a few places that used SCALE_FACTOR_NONE to load
  100P images
- Don't include 200P to supported scale factor unless
  we have 200P assets (on chromeos)

BUG=156569
TEST=covered by test.

Review URL: https://chromiumcodereview.appspot.com/11301007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@167622 0039d316-1c4b-4281-b951-d872f2087c98
17 files changed