Text shadows can now be added to a TextStyle by providing a List<Shadow>. The dart:ui Shadow class is now the base class to flutter BoxShadow.

Previously the engine would load all embedded fonts listed in the app's
font manifest during startup.  This change creates a Skia font manager that
is backed by the engine's AssetManager and can load embedded font assets
on demand.

gtest is an old version that predates the googletest and googlemock
merger, all tests should be using the newer googletest that's being
kept in sync with the upstream version.

* Merge

* Update license hash

gtest is an old version that predates the googletest and googlemock
merger, all tests should be using the newer googletest that's being
kept in sync with the upstream version.

* Added Windows support for libtxt in order to build flutter_tester.exe.

Relatively minor changes were needed to get libtxt building on Windows
(missing/incompatiable headers, the odd syscall, path separators, etc.).
Windows doesn't render text in the same way as other platforms, so some tests
that checked for specific pixel offsets are disabled.

This is for Fuchsia where we would like it to be located at //third_party/flutter.

This registers a test font manager that maps all fonts to the Ahem font

* Fix remaining ftl->fxl conversions

The previous scripting pass at this did not account for objective c file endings

* Update tonic DEPS reference to the post-fxl version

Use a generic sans-serif font family on Android that will be recognized by Skia's font manager (#4055)

This repository contains FTL now in the Fuchsia build.

This will allow us to use the common font fixtures.