iOS: Always regenerate the precompilation snapshot when building for the device

iOS: Always rebuild the FLX file

iOS: Drain and pass URLRequest body data to the platform implementation

Dart/JNI: reflection-based wrapper for the raw JNI API

Switch whitespace mode back to pre-wrap

When we removed position: sticky, we introduced a subtle line breaking
bug to pre-wrap that would cause whitespace to accumulate at the
beginning of lines that follow unclean breaks. This patch adds back the
deleted code (cleansed of the position sticky bits).

rev engine

Use the same registration process as GCM for Firebase

Fix type of nested data structures on Android

Example:
  JavaClass dateFormatClass = Java.getClass('java.text.SimpleDateFormat');
  JavaObject format = dateFormatClass.newInstance('yyyy.MM.dd');
  print(format.parse('2016.01.01').getYear());

Android support for Firebase setValue

rev engine

Support dynamic registration of mojo services on Android

SkyApplication now reads service info from a services.json file bundled
with the apk. For each service, it registers a method that invokes
connectToService on a named class. This way, third party services can
register themselves.

There's a corresponding change to flutter_tools to generate this
services.json when building an apk that depends on services.

Improve handling of window insets on Android

Now that we understand window insets, we don't need to hard-code the size of
the status bar. Also, convert the viewport metrics to be consistently in
physical pixels.

A sound pool implementation for iOS

Dart/JNI: support all field and array data types

Fix Dart/JNI string conversion to treat the data as UTF-16

Fix order of matrix operations

When rasterzing with a non-zero left and top offset, we need to apply the scale
first so that we're translating in the correct coordinate system.

Fixes https://github.com/flutter/flutter/issues/1292

Remove integration between tonic and WTFString

Remove the non-initializer version of DartInvokeAppClosure and rename
the function to the simpler DartInvoke. Also, add a special case for
DartInvokeVoid to make the callers prettier.

We use FromArguments everywhere now.

There's no reason to use WTF::Vector here over std::vector.