Chrome: Document tree search field doesn't shrink when resizing

In Chrome, resizing the document tree by dragging the "splitter" doesn't resize the search field in the Document tree part to a smaller size. Using a long search query in the search field can cause the tree to become unusable. See the screenshot.

To reproduce:

• Log in into the CMS and click "To the documents"
• Resize the document tree to the smalles horizontal size by dragging the "splitter" to the left
• In the search field, enter a long search query

Expected behaviour: Only the contents of the search bar scroll

Actual behaviour: The whole tree scrolls, including the sliders, making the tree unusable until the cursor in the search field is returned to the left