28266 Fix flaky stack-use-after-scope in PushingMutlipleFramesSetsUpNewReco… (cla: yes, embedder)

28274 Symbolize ASan traces when using run_tests.py (cla: yes, waiting for tree to go green, embedder)

28281 Eliminate unnecessary null check in fixture (cla: yes, needs tests, embedder)

28383 Started providing the GPU sync switch to Rasterizer.DrawToSurface() (platform-ios, platform-android, cla: yes, platform-fuchsia, embedder)

28407 fuchsia: Fix MissingPluginException being thrown in Dart from platform_view.cc (platform-ios, platform-android, cla: yes, platform-web, platform-macos, platform-linux, platform-windows, platform-fuchsia, needs tests, embedder)