[gtk] (30 commits) Non-fast-forward update to branch tracing

[Matthias Clasen <matthiasc src gnome org>]

The branch 'tracing' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  c060f38... gdk: Add a profiler
  760fc0f... Add a way to start the profiler
  a473b2b... frame clock: Add tracing
  ea8ae55... gsk: Add some more profiler apis
  371aa4a... gsk: Add tracing to the gl renderer
  609d663... gsk: Add tracing to the vulkan renderer
  26f3734... GtkApplication: Add a profiler dbus api
  da77616... Add docs
  1398ea3... Move gdkprofiler.h to private
  dff4113... Add an api for inserting profiling marks
  0c64b34... Don't build profiler on win32

Commits added to the branch:

  562e492... csstokenizer: Consume the \ when encountering an error (*)
  c6b2184... Allow specifying the layout manager for a widget type (*)
  e98973e... GtkHeaderBar: Don't leak decoration layout (*)
  59c6862... Use gtk_widget_class_set_layout_manager_type() (*)
  fe473db... Make get_layout_manager_type() public (*)
  ecc8f9c... Merge branch 'issue-1863' into 'master' (*)
  a8aa7af... Merge branch 'header-bar-leak4' into 'master' (*)
  759a974... Some node editor improvements (*)
  8559593... testsuite: Add a blend node test case (*)
  c886545... testsuite: Add blend-difference test case (*)
  3e21078... gl renderer: Fix blend shader (*)
  4869013... gl renderer: Fix coloring shader (*)
  b87b281... Update POTFILES.skip (*)
  7ae675b... build: Install the backend headers in the backend directori (*)
  e29cf84... broadway: Install headers (*)
  73ff7ba... Merge branch 'wip/headers' into 'master' (*)
  c6a42e9... widget: Revert the event translation change (*)
  77b7817... a11y: Stop using child-notify (*)
  68560a9... Update a11y tests (*)
  a0c6d88... Mark a failing reftest as xfail (*)
  b01cf6b... 3.96 (*)
  248c07c... Fix a compiler warning (*)
  883e186... gdk: Add a profiler
  e1d2394... Add a way to start the profiler
  ac74359... frame clock: Add tracing
  e92a1f0... gsk: Add some more profiler apis
  e73c482... gsk: Add tracing to the gl renderer
  76bd6f1... gsk: Add tracing to the vulkan renderer
  4e0c461... GtkApplication: Add a profiler dbus api
  2cc0efa... Add docs

(*) This commit already existed in another branch; no separate mail sent