[Affected versions]: Fx 57.0b11 Fx 58.0a1 [Affected platforms]: Windows 10 x64 [Steps to reproduce]: 1. Launch Firefox-ro. 2. Open a new tab. 3. Open the Onboarding tour. 4. Select the performance tab. [Expected result]: The interface is translated in romanian. [Actual result]: The description is written in english. [Regression range]: This is not a regression. [Additional notes]: a. Screenshot with the issue: https://imgur.com/a/j0Zai b. Private Browsing is also affected.