Enhance Magnifier Functionality for Cross-Mode Compatibility

[suhailshub-arch]

This pull request addresses an issue where the magnifier feature failed to synchronize correctly when scrolling across different document modes (standards mode and quirks mode).

The fix involves updating the logic for calculating scroll offsets to ensure compatibility with both modes. By prioritizing window.pageXOffset and window.pageYOffset for scroll positions which works in both standards and quirks mode, and falling back to document.documentElement.scrollLeft/document.documentElement.scrollTop where necessary (when older browsers are used), we achieve consistent behavior across all browsers and document modes.

This update ensures a seamless user experience with the magnifier feature regardless of the document rendering mode.

Note: document.documentElement.scrollLeft and document.documentElement.scrollTop only works in standards mode

[donhatch]

I don't think the || is going to work as intended.
Consider the case when window.pageXOffset is 0; then you want it to be used (if I understand correctly), but it looks like this code will use document.documentElement.scrollLeft instead (which might not exist, depending on the platform; I'm not sure what the possibilities are).

[donhatch]

Oh, I see, I guess it could still work, it's just pretty mind-bending. I withdraw my objection :-)