* Implement system fonts system channel listener

Docs improvement after seeing "null" showing up for TextWidthBasis.

This reverts commit d67f47b2.

This reverts commit ddd31bce.

Reland "Text inline widgets, TextSpan rework (#30069)" with improved backwards compatibility (#34051)

This reverts commit 14414f35.

This reverts commit 160a5680.

This reverts commit 86862c1e.

* Merge in changes for inline widgets

* Make analyzer happy, fix tests

* Fix analyzer

* Add missing doc

* Docs on RichText

* Fix analyzer some more

* Remove whitespace at end of line

* Update goldens

* Text fixes

* Analyzer

Corects a bnuch of typeos throuhgout teh Fluter codebsae.

Made use of the `misspell` tool:
https://github.com/client9/misspell

Add `textWidthBasis` param to Text to allow calculating width according to longest line.

This reverts commit 323108ff due to weird engine dependency bug

Add `textWidthBasis` param to Text to allow calculating width according to longest line.

Fix a bug where text selection handles were invisible in iOS

Will cause golden and Scuba changes. Caret will become taller and shift upwards by 2 pixels.

* Revert "Use full height of the glyph for caret height on Android (#30991)"

This reverts commit 96e1fc9c.

* Disallow cursor from appearing beyond the width of the input.

* Test that verifies the cursor can't exceed the width of the input

* Use constant from editable.dart to explain 1 pixel difference in test

* Fix failing test that tested the case of overflowing spaces

Fix the spelling errors in the dartdocs for the framework.

There are no functionality changes here, just documentation fixes.

Integrate Strut: Add StrutStyle, expose Strut API, wire up strut with dart:ui, Roll engine 31a7f4d..e7eb1c8 (7 commits) (#26332)

Includes a breaking change to dart:ui ParagraphStyle where lineHeight is renamed to height for consistency with TextStyle.

All embedders of Flutter within Google have all been updated to an
engine version that includes the const constructor added in
flutter/engine#7346 and rolled into the framework in
flutter/flutter#26252.

This reverts commit 88b77a7d.

This fixes https://github.com/flutter/flutter/issues/26390.

Usages of ParagraphConstraints (from dart:ui) whose constructor could be
const as of flutter/engine#7346 are currently marked //
ignore:prefer_const_constructors in the framework until all
Google-internal embedders have been updated to an engine version that
includes the above change. These were initially updated in engine roll
flutter/flutter#26252, but broke internal embedders.

We should re-enable use of the const constructor in those cases once
internal embedders are updated.

See: https://github.com/flutter/flutter/issues/26390

https://github.com/flutter/engine/compare/7112b72cc229...e5ec3cf3ea5c

git log
7112b72cc229e05d36716c3d7739885d3ffa72e6..e5ec3cf3ea5ce78c6c3116271601f60d30a799d4
--no-merges --oneline
e5ec3cf3e Dart SDK roll for 2019-01-08
08c95d27a Roll src/third_party/skia 55ff5d3ba881..1337f5b85978 (10
commits) (flutter/engine#7407)
e385f5cbb Roll src/third_party/skia 26d173fee72b..55ff5d3ba881 (12
commits) (flutter/engine#7406)
0f8273b0c Dart SDK roll for 2019-01-07
4036b260a Reset ParagraphBuilder after build() (flutter/engine#7401)
4820cbec4 Dart SDK roll for 2019-01-07
8eccb860d Add onStart hook to FlutterFragmentActivity
(flutter/engine#6719)
f2ea838b3 Roll src/third_party/skia b2fdcbf3033f..26d173fee72b (10
commits) (flutter/engine#7400)
5ca8aadaa Announce in/out of list (flutter/engine#6918)
4487d392d Replace Java code with equivalent, more concise code.
(flutter/engine#7398)
395b7852d Roll src/third_party/skia 46ee3f7a8ff5..b2fdcbf3033f (11
commits) (flutter/engine#7394)
5965f9084 Make `ParagraphConstraints` have const constructor
(flutter/engine#7346)
e02dd416a Roll src/third_party/skia a47eb455360f..46ee3f7a8ff5 (2
commits) (flutter/engine#7390)
f0038b3cc Roll src/third_party/skia 3ac3a4053f86..a47eb455360f (2
commits) (flutter/engine#7389)

* Fix bug in calculation of downstream text distance when aligned: right

* After having affinity explained to me, match getOffset and tests to
expected behavior

* Clean up test formatting and fix analyze errors

* Improve test comments and reorganize a bit

* Specify logical pixels

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests