If a feature branch is behind default, you can sync that branch, using a merge, into your feature branch.

1. From the left-side menu, hover your mouse over the right side of the Branches label under you see the word Show.
   
   
2. Click Show to expand the list of branches.
   
3. Double-click the feature branch that is behind to switch to that branch.
4. マージ ボタンをクリックします。
5. From the popup that appears, select the commit you want to merge into your feature branch.
   
6. OK をクリックします。
7. You'll notice that you need to commit your changes. Click the Commit button at the top. The commit message defaults to a description of Merge. Go ahead and click Commit.
   Your feature branch now has all the commits that your default branch has.