Some components in the Flutter engine were derived from the forked blink codebase. While the forked components have either been removed or rewritten, the use of the blink namespace has mostly (and inconsistently) remained. This renames the blink namesapce to flutter for consistency. There are no functional changes in this patch.

So our future pull requests won't be polluted by the white space changes.

* add path measure

* fix typo

* getBound and addPathWithMatrix

* Add myself to Authors, add PathOps

* fix linting issues

* update licenses_flutter to add new files

* Use matrix4 instead of matrix3 for consistency/interop

* put pubspec back

* fix bug in getSegment

* fix typo

* Add return value for PathOp

* refactoring from review

* refactoring from review - still TBD on computeMetrics()

* add doc

* lint issue

* fix computeMetrics, add Path.from

* add missing wireup for clone

* change PathMetrics to iterable, fix bug with angle on Tangent

* prefer std::make_unique

* cleanup docs

* add path measure

* fix typo

* getBound and addPathWithMatrix

* Add myself to Authors, add PathOps

* fix linting issues

* update licenses_flutter to add new files

* Use matrix4 instead of matrix3 for consistency/interop

* put pubspec back

* fix bug in getSegment

* fix typo

* Add return value for PathOp

* refactoring from review

* refactoring from review - still TBD on computeMetrics()

* add doc

* lint issue

* fix computeMetrics, add Path.from

* add missing wireup for clone

* change PathMetrics to iterable, fix bug with angle on Tangent

* prefer std::make_unique

* cleanup docs

* fix iterator bug

* remove unnecessary clone for computeMetrics

* fix some doc issues

* fix PathMeasure iterator, extendWithPath, isClosed, and pubspec.lock

* get rid of orElse; use StateException

* StateError, not StateException

* doc improvements and nits

* add unit tests, fix bugs found during testing

* fix two uncommited doc changes

* one more

* change sign of tangent angle, update docs

* update unit tests for inverted angle

* update tangent to include vector

* Doc fixes

* Fix MSVC compilation and unit test

* Revert "Add support for measuring, combining, and getting bounds of Path objects  (#4799)"

This reverts commit 8c00101a, as it broke engine build bots on Linux and Windows.

* add path measure

* fix typo

* getBound and addPathWithMatrix

* Add myself to Authors, add PathOps

* fix linting issues

* update licenses_flutter to add new files

* Use matrix4 instead of matrix3 for consistency/interop

* put pubspec back

* fix bug in getSegment

* fix typo

* Add return value for PathOp

* refactoring from review

* refactoring from review - still TBD on computeMetrics()

* add doc

* lint issue

* fix computeMetrics, add Path.from

* add missing wireup for clone

* change PathMetrics to iterable, fix bug with angle on Tangent

* prefer std::make_unique

* cleanup docs

* add path measure

* fix typo

* getBound and addPathWithMatrix

* Add myself to Authors, add PathOps

* fix linting issues

* update licenses_flutter to add new files

* Use matrix4 instead of matrix3 for consistency/interop

* put pubspec back

* fix bug in getSegment

* fix typo

* Add return value for PathOp

* refactoring from review

* refactoring from review - still TBD on computeMetrics()

* add doc

* lint issue

* fix computeMetrics, add Path.from

* add missing wireup for clone

* change PathMetrics to iterable, fix bug with angle on Tangent

* prefer std::make_unique

* cleanup docs

* fix iterator bug

* remove unnecessary clone for computeMetrics

* fix some doc issues

* fix PathMeasure iterator, extendWithPath, isClosed, and pubspec.lock

* get rid of orElse; use StateException

* StateError, not StateException

* doc improvements and nits

* add unit tests, fix bugs found during testing

* fix two uncommited doc changes

* one more

* change sign of tangent angle, update docs

* update unit tests for inverted angle

* update tangent to include vector

* Doc fixes

We need to release the typed array so that we can allocate the result value.

Fixes https://github.com/flutter/flutter/issues/6456

This removes most (all?) of our dependency on base::RefCountedThreadSafe.

Also, switch over to //lib/tonic's typed data classes.

These parts don't depend on engine anymore. Also reformat them to match Google
C++ style.