19067 Make upscaling opt in for image decoding (cla: yes, perf: memory)

19283 Make Shell::NotifyLowMemoryWarning trace (cla: yes, perf: memory, waiting for tree to go green)

affects: engine - 3 pull request(s)

18492 fuchsia: Fix runtime_tests and shell_tests (affects: engine, bug, cla: yes, waiting for tree to go green)

19003 Move fuchsia/scenic integration behind #define (affects: engine, cla: yes, code health, platform-fuchsia)

19132 Add PlatformView support for Fuchsia (affects: engine, cla: yes, platform-fuchsia)

affects: tests - 3 pull request(s)