Previously we enabled accessibility unconditionally on iOS, which is more
expensive than necessary. We still enable it unconditionally on the simulator
because there's no API for determining whether accessibility is needed on the
simulator.

Fixes #4849

Package map entries can contain relative paths.
See related commit: d7d99c62

Add a --pause-isolates-on-start flag to the flutter mojo content
handler to match the one that's supported by the dart mojo content
handler.

Fixes: https://github.com/flutter/flutter/issues/4802

These classes now use the same terminology and work in the same way.
Also, change semantics.mojom to use an enumeration of actions instead of
having a separate method per action. This will hopefully scale better.

* Update to mojo fd8d18dbf7a4f9ed8a607648cca6d2c595b1c580

* Update mojo_sdk

* Update to account for Mojo API changes

* Backport to older base

It's empty and is easily confused with onPostResume

This will make it simpler to write listeners that can be reused in multiple
applications.

Fix leaky descriptor in dart_init and use the correct macro to handle EINTRs on close syscall wrappers. (#2765)

* Use IGNORE_EINTR instead of HANDLE_EINTR when using the `close` syscall wrapper.
* Don't leak the file descriptor used to memory map Dart related artifacts.

Updating base turns out to be more complicated than I thought.

This reverts commit daa822aa.
This reverts commit c38428c7.
This reverts commit 4b73a8a0.

Update base, gn, and their clients.

The upstream mojo.git no longer contains this code.

- [x] Wire up synchronous script reloading in the library tag handler.
- [x] Allow glfw sky_shell to start from dart source as well as bundle.

This patch disentangles dart:jni from //sky/engine and moves it into
//flutter/lib/jni. Eventually dart:ui will move into a peer directory.

Now that tonic doesn't depend on anything in //sky/engine anymore, we
can move the code to a location where its dependencies are clearer.

According to hackbod on Stack Overflow, we're supposed to block in the
surfaceCreated callback until we've actually drawn into the surface:

http://stackoverflow.com/questions/8772862/surfaceview-flashes-black-on-load/8888108#8888108

1) Add ability to specify a system UI overlay style, to
   provide a hook into the style of the status bar icons on iOS.

2) Migrate the Activity service's task description API to the
   system chrome platform service. The old API will be removed
   once the Flutter repo is updated to use the new API after an
   engine roll.

flutter/flutter#3544

This patch makes the FlutterViewController interface more idiomatic by not
retaining listeners. It's the callers responsibility to make sure the lifetimes
work out.

Tools can send a broadcast intent that will cause Flutter processes to
write their names and observatory ports to the log in JSON format.

* Update to mojo 7d579155cc597aa3befcbfad66eef54bda06b57c

* Update to new API

Previously we'd draw uninitialized memory. Now we draw black.

Fixes #3447

* Close the app after the user acknowledges the Launch Error alert.

This enables the specification of a local engine (via `--local-engine`)
for flutter tools to use.

It crashes. We either need to make it safe to call before
Dart_Initialize on Mac or we need to use some other way of measuring
startup time.

Fixes #4006

When developing the engine from Xcode, it is useful to see log output in Xcode's UI. We were redirecting streams away so that the tools could pick read these logs. With the change to the scheme, when running from Xcode, the logs will show up in Xcode's UI. When, running from the tools, that flag will not be present and the tools will work as they always have.