This updated the native embedder API in a non-ABI breaking way.

This retains gamut correction (adjusting colors for screens with different capabilities), but does all blending and interpolation with sRGB-encoded values. That matches the behavior expected by most users, as well as the behavior of nearly all other systems. It also greatly simplifies the EGL code.

A future Skia change will make this behavior more of a first-class citizen, so some of these implementation details will change again, but the behavior will not. The bulk of this change (elimination of complication from the GL surface code) is permanent - it's just the SkColorSpaceXformCanvas that will be replaced.

[Android] Allow persisting a FlutterNativeView across activities.

Fixes https://github.com/flutter/flutter/issues/12996

This reverts commit 0b7582e6.

* Roll skia to 0658f7

* Update licenses

Adding Rect.expandToInclude and Rect.longestSide to make the Rect API more symmetric.

Fixes https://github.com/flutter/flutter/issues/12886

Fixes https://github.com/flutter/flutter/issues/12924

A flutter_app target might be declared in a build file alongside some host tool.
The intent of the assertion seemed to be restricting the use of the template to the Fuchsia codebase.

* 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

Plumb through Scenic display metrics to use during
Preroll.

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.

On iOS 11 and above, update viewport padding and notify the framework
when changes to safe area insets occur.

https://github.com/flutter/flutter/issues/204

There are two different sets of view insets that applications may want
to track in order to avoid unwanted interaction with system UI:

1. OS UI that effectively shrinks the Flutter view from a UX point of
   view: e.g., when the keyboard opens, it occludes the bottom of the
   screen and the view should be adjusted such that the bottom, for the
   purposes of scrolling is just above the keyboard.
2. OS UI that is overlaid over the application, but into which the
   application should draw. e.g., the Home indicator on the iPhone X
   typically appears near the bottom of the screen, overlaid over app
   content. Content should be rendered within this 'safe area' but apps
   should avoid requiring user interaction there. For example, list
   views may want to include some small amount of additional padding to
   ensure the last list item can scroll above this area.

Since Flutter does not currently distinguish between these two cases,
this patch disables the bottom safe area inset until API is added to
support these separately.

This is the first step to support animated GIFs: flutter/flutter#204

TBD in following CLs:
 * Implement Codec.getNextFrame.
 * Add Framework side support to run animations.

Previously it always fell through to a zero-length character range at
the specified position.

Update the package() template to match the new syntax. This change keeps this
package working the same way it does currently (i.e., being included in the
system image). In the future, we'll want to remove this annotation and separate
this package from the system image.