Revert longPress/Tap and Gallery changes

It allows callers to account for things like shadows that paint
outside the bounds of the widget.

https://github.com/flutter/flutter/issues/16859

It should account for the device pixel ratio

https://github.com/flutter/flutter/issues/16859

https://github.com/flutter/flutter/issues/16859

See https://github.com/flutter/flutter/pull/15383

Use a space instead of a zero-width space to calculate the preferred height of a line of text (#16972)

The zero-width space character may not be supported by the font requested in
the text style.  If that happens, then libtxt will fall back to another font
to render that character, resulting in text metrics that do not match the
intended font.

Fixes https://github.com/flutter/flutter/issues/16257

* Set text direction in semantics along with Directionality

* update tests for the extra SemanticsNode

New a11y traversal:

- sort direct sibling SemanticsNodes only
- use new sorting algorithm
- implement RTL
- test semantics in traversal order by default
- add AppBar traversal test
- breaking: remove nextNodeId/previousNodeId from the framework
- breaking: remove DebugSemanticsDumpOrder.geometricOrder

When passing a Color object with same R/G/B code ( e.g. [new Color.fromRGBO(100, 100, 100, 1.0)] ) to HSVColor.fromColor(Color color) , the hue in return will be NaN .

As pointed out in the bug, the issue is fixed by just clamping sizeFactor.value.

Fixes #16247 

This adds a toImage function to RenderRepaintBoundary that returns an uncompressed raw image of the RenderRepaintBoundary and its children. A device pixel ratio different from the physical ratio may be specified for the captured image. A value of 1.0 will give an image in logical pixels.

This addresses #16593 by removing the unneeded assert in the setter for constrainedAxis. Null was meant to be allowed there.

This replaces #16599 and fixes #16593, reported by @maksimr

* log error when calling setState in constructor

Semantics object support for edge triggered semantics 

This chip demo is more interactive than the last one, trying to exercise all of the types of chips for a demo that lets you select different types of "chips" (like tortilla, wood, micro, etc.), and then filter them and select an action on them.

* Fine-tune iOS's scroll start feel

* remove negations in doc

* Our own dart-side gesture arena also contributes to the 'jerk'. Make sure that snap is accounted as well.

* Added more code comments from review.

Fixes #14590.

This is a PR giving some love to the abandoned PR #16263 by @harrisonturton

I've added a test, and formatted it to be readable.

Currently the CircleAvatar does not set a fit property on the DecorationImage it uses to paint images. This causes non-square images to not fully cover the circle, which looks pretty bad. This PR sets it to BoxFix.cover.

Fixes #13478.

Adding some tests for onTapDown and onTapCancel for the InkWell, as suggested in post-submission comments by @Hixie in #16190.

Also, added those to the diagnostic output.

Support summary-details tree view.

Adding missing docs to the forceRebuild function in the widget inspector.

* add localizations for navigation menu, popup menu, dialog, and alert

Support exposing the InspectorService over the Flutterservice extension protocol as well as the observatory protocol. (#15876)

* Support exposing the InspectorService over the Flutter
service extension protocol as well as the observatory protocol.

We will probably remove most of the observatory protocol support once a
couple versions of the Flutter IntelliJ plugin have shipped that use the
Flutter service extension protocol. The only reason to continue supporting
the observatory protocol is it will allow using the inspector when paused
at a breakpoint.

We don't really like the name AnimatedChildSwitcher, and we think that AnimatedSwitcher might be better (since the Child part is redundant). We also considered AnimatedChild, AnimatedTransition and AnimatedReplacement (among others).

Nothing in here besides a rename.