8920 Replace Skia font macros with enums. (cla: yes)

8923 [fuchsia] Guard out-of-tree Fuchsia targets to fix in-tree build (cla: yes)

8927 libtxt: add a BoxHeightStyle option based on the height of the strut (cla: yes)

8928 Update skew Docs (cla: yes)

8930 Fix iOS crash when in background for 3 minutes (cla: yes)

8936 Wire up the Skia Metal backend on iOS. (cla: yes)

8937 Add a minimal set of symbols to the dynamic symbol table for Linux executables (cla: yes)

8939 Move the Fuchsia Flutter Runner to //flutter/shell/platform/fuchsia/flutter (cla: yes)

8940 Roll Tonic (cla: yes)