Implement a finch experiment for compositing opaque fixed position elements |
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Issue descriptionVersion: 56+ OS: All Eng owner: flackr Having a finch experiment in place will provide us with data for evaluating the performance change for compositing opaque fixed position elements. See issue 626200 for the primary feature implementation bug. Finch/experimentation: This should affect the following metrics: Event.Latency.TouchToScrollUpdateSwapBegin - Expect to see a reduction in this metric on low DPI touch devices due to more composited scrolling. Renderer4.MainThreadGestureScrollReason - Expect to see "Not scrolling on main" increase with a reduction in "Non layer viewport constrained objects" Renderer4.MainThreadWheelScrollReason - Expect to see "Not scrolling on main" increase with a reduction in "Non layer viewport constrained objects"
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Nov 22 2016
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Jan 13 2017
The following revision refers to this bug: https://chromium.googlesource.com/chromium/src.git/+/96f33ef6f7c21303a68dc52c3e27a925fb200ce5 commit 96f33ef6f7c21303a68dc52c3e27a925fb200ce5 Author: flackr <flackr@chromium.org> Date: Fri Jan 13 22:05:44 2017 Revert "Round the scroll offset synced back to main instead of flooring." and disable CompositeOpaqueFixedPosition Reverts the commit 75a7e4cb1ec29ded2e52539259233356caa883c8 (https://codereview.chromium.org/2511473003) and additionally disables CompositeOpaquePosition by default as that commit fixed a compositing bug exposed by compositing more fixed position elements ( https://crbug.com/663291 ). Rounding the synced scroll offset introduced a regression which caused scroll position to become unstable when zoomed in on long sites. TBR=weiliangc,boliu BUG= 677686 , 663291 , 661754 CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel Review-Url: https://codereview.chromium.org/2629793003 Cr-Commit-Position: refs/heads/master@{#443691} [modify] https://crrev.com/96f33ef6f7c21303a68dc52c3e27a925fb200ce5/android_webview/javatests/src/org/chromium/android_webview/test/AndroidScrollIntegrationTest.java [modify] https://crrev.com/96f33ef6f7c21303a68dc52c3e27a925fb200ce5/cc/trees/layer_tree_host_impl_unittest.cc [modify] https://crrev.com/96f33ef6f7c21303a68dc52c3e27a925fb200ce5/cc/trees/layer_tree_host_unittest_scroll.cc [modify] https://crrev.com/96f33ef6f7c21303a68dc52c3e27a925fb200ce5/cc/trees/property_tree.cc [modify] https://crrev.com/96f33ef6f7c21303a68dc52c3e27a925fb200ce5/content/child/runtime_features.cc [modify] https://crrev.com/96f33ef6f7c21303a68dc52c3e27a925fb200ce5/content/public/common/content_features.cc [modify] https://crrev.com/96f33ef6f7c21303a68dc52c3e27a925fb200ce5/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in
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Jan 18 2017
The following revision refers to this bug: https://chromium.googlesource.com/chromium/src.git/+/b0e7600a8072b74faaccbddd2d90fd8130c5fc67 commit b0e7600a8072b74faaccbddd2d90fd8130c5fc67 Author: Alex Mineer <amineer@chromium.org> Date: Wed Jan 18 02:11:36 2017 Revert "Round the scroll offset synced back to main instead of flooring." and disable CompositeOpaqueFixedPosition Reverts the commit 75a7e4cb1ec29ded2e52539259233356caa883c8 (https://codereview.chromium.org/2511473003) and additionally disables CompositeOpaquePosition by default as that commit fixed a compositing bug exposed by compositing more fixed position elements ( https://crbug.com/663291 ). Rounding the synced scroll offset introduced a regression which caused scroll position to become unstable when zoomed in on long sites. TBR=weiliangc,boliu BUG= 677686 , 663291 , 661754 CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel (cherry picked from commit 96f33ef6f7c21303a68dc52c3e27a925fb200ce5) Review-Url: https://codereview.chromium.org/2629793003 Cr-Original-Commit-Position: refs/heads/master@{#443691} Cr-Commit-Position: refs/branch-heads/2924@{#791} Cr-Branched-From: 3a87aecc31cd1ffe751dd72c04e5a96a1fc8108a-refs/heads/master@{#433059} [modify] https://crrev.com/b0e7600a8072b74faaccbddd2d90fd8130c5fc67/android_webview/javatests/src/org/chromium/android_webview/test/AndroidScrollIntegrationTest.java [modify] https://crrev.com/b0e7600a8072b74faaccbddd2d90fd8130c5fc67/cc/trees/layer_tree_host_impl_unittest.cc [modify] https://crrev.com/b0e7600a8072b74faaccbddd2d90fd8130c5fc67/cc/trees/layer_tree_host_unittest_scroll.cc [modify] https://crrev.com/b0e7600a8072b74faaccbddd2d90fd8130c5fc67/cc/trees/property_tree.cc [modify] https://crrev.com/b0e7600a8072b74faaccbddd2d90fd8130c5fc67/content/child/runtime_features.cc [modify] https://crrev.com/b0e7600a8072b74faaccbddd2d90fd8130c5fc67/content/public/common/content_features.cc [modify] https://crrev.com/b0e7600a8072b74faaccbddd2d90fd8130c5fc67/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in
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Jan 24 2017
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Apr 27 2017
The Finch experiment is not a P1. Could you update the bug with the current situation?
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Sep 12 2017
This issue has been automatically relabelled type=task because type=launch-owp issues are now officially deprecated. The deprecation is because they were creating confusion about how to get launch approvals, which should be instead done via type=launch issues. We recommend this issue be used for implementation tracking (for public visibility), but if you already have an issue for that, you may mark this as duplicate. For more details see here: https://docs.google.com/document/d/1JA6RohjtZQc26bTrGoIE_bSXGXUDQz8vc6G0n_sZJ2o/edit For any questions, please contact owencm, sshruthi, larforge
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Feb 28 2018
The finch experiment showed a reduction of main thread scrolls due to viewport constrained position of about 4% on desktop, we may be able to do better by improving our detection of cases where LCD text can be preserved or isn't necessary (i.e. no text) but even this improvement is substantial. We are close to being able to enable this by default. |
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Comment 1 by bugdroid1@chromium.org
, Nov 4 2016