* Roll dart

* Update license

* Roll Skia and remove PngPixelSerializer

* Update licenses

Dart roll to cf1de7d46cd88e204380e8f96a993439be56b24c (#4457)

* Roll Skia to 58a3fcd4b3a2f7210586f4ec74dde8ac2b231e0f

* license again

* Roll dart to 962c18b627c76f22166cd0bb8ab9e1b21d3c7305.

* Update travis/licenses_golden/licenses_third_party

* Roll dart to f5fc335a4cdfcf96ae550044c64044ffe599e595

* Update license hash

* Roll a little further to pick up a revert

* Update hash

* Roll dart version in flutter engine.

* Update license file.

As we anyway always recommend to set the target_os to android.
Also if you happen to not set the target_os to android it messes up the licenses script output.

Picks up:
1. Windows support for flutter tester
2. Spaces in Dart package paths in the loader.

* roll to 09b8c91b696925c6c6a25c35173f2da27abf0fbe

* update licenses

* Roll skia to 0658f7

* Update licenses

* Roll dart

* Update license hash key, no changes to licenses themselves

With the update to HEAD of the Fuchsia buildtools repo, the new clang
toolchain picked up caused link-time breakage in android x86_64
libFlutter.so builds.

Sample log:
https://build.chromium.org/p/client.flutter/builders/Linux%20Engine/builds/1974/steps/build%20android_debug_x64/logs/stdio

Sample failure:
FAILED: libflutter.so libflutter.so.TOC lib.stripped/libflutter.so
../../third_party/android_tools/ndk/toolchains/x86_64-4.9/prebuilt/linux-x86_64/lib/gcc/x86_64-linux-android/4.9.x/../../../../x86_64-linux-android/bin/ld.gold: error: obj/flutter/shell/platform/android/libflutter/android_context_gl.o: unsupported reloc 42 against global symbol std::__ndk1::num_put<char, std::__ndk1::ostreambuf_iterator<char, std::__ndk1::char_traits<char> > >::id

This reverts commit 8ad42f0d.

* Roll garnet to b3ba6b6d6ab8ef658278cc43c9f839a8a8d1718e

Also includes a buildroot patch to pick up new dependency:
  build/config/fuchsia/sdk.gni

This fixes a build breakage in
garnet/public/lib/fxl/strings/string_view_unittest.cc wherein a variable
'sw5' was declared but the test erroneously tested against 'sw4' from
the previous test.

* Update license script for garnet

Reflects structural changes in directories we do not depend on. This
filters out the following directories in addition to what was already
filtered:
  garnet/drivers
  garnet/packages
  garnet/public/build/
  garnet/public/rust/

* Update licenses

Update to moved repository.

Issue https://github.com/flutter/flutter/issues/9998

* Roll Fuchsia buildtools to 85907c59e97527d79bbfdfd849d8e85c24959cc5

This also updates Flutter buildroot to a6e52dbb776c45cc8c57d7143b8eb8b2e762fdfb
which disables -Wtautological-constant-compare temporarily until
https://reviews.llvm.org/D39462 lands in clang. This is in line with
Fuchsia's compiler options.

* Apply clang-format diffs

No logical changes. This applies clang-format from the latest Fuchsia
buildtools to the engine codebase.

This reverts commit 4caa68b8.

This reverts the previous roll to 33397f which included an assertion we ended up tripping over on certain scenes. A Skia issue has been filed for this https://bugs.chromium.org/p/skia/issues/detail?id=7225.