...and document what I did.

In order to allow chips to be properly drawn when they expand in size (without
using IntrinsicHeight), I needed a BoxDecoration shape that would be dependent
upon the rendered height of the widget. This seemed to be pretty generally
useful, so I added a new ShapeDecoration called StadiumBorder. It uses the
minimum dimension to adjust the BorderRadius of a rounded rect in the shape
decoration.

I also converted some uses of BoxShape to be case statements, updated the
chips to use the StadiumBorder decoration, and updated some of the metrics to match
the Material spec, as well as implementing lerping to and from StadiumBorder.

* Introduce a Directionality inherited widget which sets the ambient LTR vs RTL mode (defaulting to null, which means you cannot use directionality-influenced values).

* Make it possible to configure Padding (including Container.padding and Container.margin) using a directionality-agnostic EdgeInsets variant.

* Provide textDirection and verticalDirection controls on Row and Column to make them RTL-aware.

* Introduce a variant of FractionalOffset based on the EdgeInsets variant. Not yet actually used.

* Fix all the tests that depended on Row defaulting to LTR.

* Wrap the label widget of the Chip in a Flexible. (#11523)

* This allows the Chip to constrain the size of its content after taking into account the space occupied by the avatar and delete icon (if they are present)

* Adding unit tests to evaluate correct size constraints of the Chip widget's label. (#11523)

* Minor change in formatting.

* Adjust function formatting.

* Adds more customization options to the Chip widget

Includes:
- Custom Tooltip message for the delete button;
- Custom background color for the chip
- Custom delete icon color
- Custom label text style

* Adds missing type annotations to tests and improves documentation.

* Tweaks labelStyle field documentation

* Provide haptic/acoustic feedback for tap & long-press on Android

* review comments

* fixed example code

* review comments

* comment fix

Moved everything icons related except the material icon button and the materialicon font list to widget

backgroundColor -> color
backgroundImage -> image
BackgroundImage -> DecorationImage

* use color.shadeXxx instead of color[Xxx]

* remove calls to .shade500 on MaterialColor

* remove calls to .shade200 on MaterialAccentColor

* fix test

Covers lib/ in package:flutter.

* Added custom radii to RRect.

This is the first commit towads an implementation of
MergeableMaterial. It adds custom radii to RRect.

* Renamed RRect constructors and added BorderRadius.

BorderRadius is a class similar to EdgeInsets that lets you define
all rounded corners of a rounded rectangle easily.

Anywhere that accepted IconData now accepts either an Icon or an
ImageIcon.

Places that used to take an IconData in an `icon` argument, notably
IconButton and DrawerItem, now take a Widget in that slot. You can wrap
the value that used to be passed in in an Icon constructor to get the
same result.

Icon itself now takes the icon as a positional argument, for brevity.

ThemeData now has an iconTheme as well as a primaryIconTheme, the same
way it has had a textTheme and primaryTextTheme for a while.

IconTheme.of() always returns a value now (though that value itself may
have nulls in it). It defaults to the ThemeData.iconTheme.

IconThemeData.fallback() is a new method that returns an icon theme data
structure with all fields filled in.

IconTheme.merge() is a new constructor that takes a context and creates
a widget that mixes in the new values with the inherited values.

Most places that introduced an IconTheme widget now use IconTheme.merge.

IconThemeData.merge and IconThemeData.copyWith act in a way analogous to
the similarly-named members of TextStyle.

ImageIcon is introduced. It acts like Icon but takes an ImageProvider
instead of an IconData.

Also: Fix the analyzer to actually check the stocks app.

This reverts commit 55f9145e.

Turns out that this commit breaks apps that use the material library,
because of the _errorTextStyle DefaultTextStyle which has inherit:true.
Just setting it to false doesn't work, unfortunately, because then you
hit some sort of issue with merging that text style with others that
have inherit:true.

To make it clear that this constructor requires an explicit style. Also
throw a descriptive error recommending the inherit constructor for
styles with the inherit bit set.

Fixes #3842

The dartdoc will continue until morale improves.

Also, clean up a few interfaces that looked awkward when writing docs.

Also, fill out other documentation for these widgets.

Fixes #967

* justifyContent -> mainAxisAlignment
* alignItems -> crossAxisAlignment
* FlexJustifyContent -> MainAxisAlignment
* FlexAlignItems -> CrossAxisAlignment

Fixes #231

This patch renames StatelessComponent to StatelessWidget and
StatefulComponent to StatefulWidget.

Fixes #2308

Fixes #1382

Rather than managing all the Material Design icons manually, we now
manage them using an icon font. The icon font contains glyphs for each
icon in an efficient vector format.

This patch updates the FLX tooling to include the MaterialIcons font and
updates the Icon widget to use the font instead of asset images.

Fixes #2313
Fixes #2218
Fixes #2009
Fixes #994

Now you can colorize an Icon simply by proving a Color for the Icon.

Previously we used a positional argument for widgets that had multiple
children. Now we use a named argument that defaults to an empty list.

Fixes #241

After this patch, if you try to use a widget that depends on being enclosed in
a material, you now get an assert and a debugPrint if you're not inside a
material.

Fixes #243

Fixes #464

http://www.google.com/design/spec/components/chips.html#chips-behavior

This patch adds support for deletable and non-deleteable chips, but doesn't yet
add support for contact chips. Also, demo the chips in a new Material Gallery
app that will let us demo our gallery of widgets in a single app.