No more caching volatile bitmaps

VideoFrames are always marked as volatile and load_yuv_texture() was caching everything, even volatile bitmaps. To solve this issue, we no longer cache volatile bitmaps' YUV planes in load_yuv_texture().

There is another issue which cause this to happen, related to how VideoImageGenerator::onGetYUV8Planes() is implemented, which is logged here: crbug.com/455235

BUG=450706, 450699

Review URL: https://codereview.chromium.org/900943002
1 file changed