Android Support Library v7: Error retrieving parent for item

Question

You must make the android-support-v7-mediarouter project "aware" of the android-support-v7-appcompat project as a referenced library.

1. Right click android-support-v7-mediarouter project, select Properties
2. Select Android
3. In the Library section at the bottom, click Add....
4. Select android-support-v7-appcompat in the dialog.
5. Click Apply.
6. Click OK.
7. Do a clean build on the android-support-v7-mediarouter project.