manifest: Use master branch for chromium-webview

* The exact same prebuilt binaries are used across lineage releases,
  so let's eliminate the maintenance overhead of needing to pick
  updates across branches.

Change-Id: If2b11de25eee13656a1687a6d2db8e2f6da4bf80
1 file changed
tree: 2b0b31c17332f10c098b508dc7b5e30a2f558d47
  1. snippets/
  2. default.xml
  3. README.mkdn