Cleans up header order/grouping for consistency: associated header, C/C++ system/standard library headers, library headers, platform-specific #includes.
Adds <cstring> where strlen, memcpy are being used: there are a bunch of places we use them transitively.
Applies linter-required cleanups. Disables linter on one file due to included RapidJson header. See https://github.com/flutter/flutter/issues/65676
This patch does not cover flutter/shell/platform/darwin. There's a separate, slightly more intensive cleanup for those in progress.
Tonic used to be used by multiple consumers outside of Flutter Engine. Due to
this, it has an unnecessary abstraction layer as well as utilities duplicated in
FML and other engine subsystems. The sole user of Tonic is now the Flutter
Engine. It is intended that the Flutter Engine team now owns this subsystem,
remove unnecessary utilities and document the headers. This is the first step in
the transition. No history is being imported as the initial history was already
lost in the transition of this component to fuchsia.googlesource. As this
component was unmaintained there, I could see no additional value in importing
the history of the patches there.
No functional change. Just moved the repo from //third_party to
//flutter/third_party and updates GN refs.
