GitLab

aura::Env::CreateInstance() takes a type. This patch plumbs the type
through to content::MainFunctionParams and Content::ConteintMainParams
so that consumers can specify how they want Env configured.

BUG=672932
TEST=none
R=jam@chromium.org

Review-Url: https://codereview.chromium.org/2567113002
Cr-Commit-Position: refs/heads/master@{#438023}