The changes in issue 776713 seems to be related?

This feels like it has to come from the image decoders, as it's modifying both discardable and GPU mem.

There's a change by Khushal (https://chromium-review.googlesource.com/c/chromium/src/+/935441) which *could* potentially increase gpu memory, as it causes Bitmap (non-lazy) images to be decoded/uploaded *if* they are scaled. However, I'd expect this change to do the opposite - reduce gpu memory by uploading smaller images and increase discardable by decoding /caching scaled discardable versions of bitmaps. Khushal, can you think of anything that might explain this?

There were a couple of image caching changes that went into 66.0.3356.0. The one above and https://chromium.googlesource.com/chromium/src/+/cace4d4608929f1febdba2a1535c111945afe1fd. But both of these were fixes to the change that moved caching of image uploads from skia to cc that went in the previous version (https://chromium-review.googlesource.com/912692). If we were not changing behaviour with respect to this caching earlier happening in skia, I would have expected no change overall.

But looks like the initial change that added uploading of bitmaps to cc had no impact and the changes above did? What you said above is what I would have expected to, more discardable memory from caching of scaled bitmaps and less gpu memory due to lower size of uploaded image. The other change which was fixing caching of canvas snapshots made sure we don't re-upload multiple copies of the same image, so that should have resulted in less gpu memory also.

Interestingly, the gpu memory recovered in the next version (66.0.3359.14), and I don't see any change related to the above ones between these 2 versions.

This bug has an owner, thus, it's been triaged. Changing status to "assigned".