Update WebView manifest to target/minSDK 21.

Bug: 16902981
Change-Id: I44594b62e94b034662b30f9e43a65946224c3152
(cherry picked from commit 8473b38625fa761e77c4b247e688b28755723dd9)
1 file changed
tree: 1ffc2274b5380ad21ad33ccacf9e69250fe0e687
  1. Android.mk
  2. chromium/
  3. nullwebview/