Chrome extension to fit frames to content
Fits iframe height to its content, to help avoid nested scroll bars on complex web pages. Right-click on a web page and select the menu item "Frame-Fit: adjust frame height". Or, use a keyboard shortcut to run the extension (default: Crtl-Shift-Y).
A green message will briefly appear after resizing is complete. Refresh the page to go back to the original format. If no action was possible, a yellow message will appear.
Disclaimer: Note that due to the near-infinite variety of web page designs, this extension may not be able to detect and adjust the height to display as desired. If it works for you, great. If not, be assured it will do no harm and feel free to uninstall it -- it won't hurt our feelings.
To work with file URLs you'll need to grant extra permissions by opening the extension details and turning on "Allow access to file URLs". Otherwise, it will quietly do nothing on a page with file URLs.