Version: m51 and on
OS: All

What steps will reproduce the problem?
(1) Go to http://www.vox.com/2015/5/14/8605917/highways-interstate-cities-history and look at one of the "slide to reveal then and now" panes
(2) Note the jitter as the slider moves

What is the expected output?
Stable appearance of the image as the size changes but the scale remains the same

What do you see instead?
Pixels from the source seem to move around in the destination as the size changes, even though the mapping from source to dest should be completely

This bug is forked from https://bugs.chromium.org/p/chromium/issues/detail?id=585741
The test case from that example is attached here.

Off-bug discussion suggests the following fix:
- Change the image cache to enable searching for a given image, at a given scale
- When looking for an image, look for bigger images at the same scale that contain the requested image. If found, just subset that image.
- If a smaller image is found, and the source contains it, increase the size of the resampled image in the cache

An alternate approach is to detect potential animation and set the filter quality to low.
 

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