Now that we understand window insets, we don't need to hard-code the size of
the status bar. Also, convert the viewport metrics to be consistently in
physical pixels.

Fix order of matrix operations

When rasterzing with a non-zero left and top offset, we need to apply the scale
first so that we're translating in the correct coordinate system.

Fixes https://github.com/flutter/flutter/issues/1292

Remove integration between tonic and WTFString

Remove the non-initializer version of DartInvokeAppClosure and rename
the function to the simpler DartInvoke. Also, add a special case for
DartInvokeVoid to make the callers prettier.

We use FromArguments everywhere now.

There's no reason to use WTF::Vector here over std::vector.

We used to share memory between Dart strings and WTF::String objects by
way of the Dart externalized strings. That used to be important when the
DOM shared many strings between C++ and Dart. However, now that we don't
retain strings in C++ much anymore, we don't need this complexity.

This patch removes DartStringCache and the integration. It also unwinds
several cases where we were converting back and forth between
WTF::String and std::string for no reason. Now we use std::string more
consistently.

For the case of ParagraphBuilder::addText, we now take a raw const
char*, which more closely matches the API the DartVM exposes. That means
we do a single copy out of the VM and into the render tree at that
point.

Move microtask queue into tonic

Moving the microtask queue into tonic solves three problems:

1) Removes three levels of indirection when invoking microtask
callbacks.
2) Removes the sky/engine/dom directory entirely.
3) Removes the last client of the (inefficient) DartValue class.

FontWeight.lerp

setTaskDescription: Guard against bad values from Dart.

Color.opacity

We used to crash if you set a non-opaque colour.

Sometimes you want the alpha channel as a double rather than an int.
For convenience, provide an accessor on Color that returns this.

Also, fix FontWeight.toString and add some type annotations on the constants.

Path service implementation for iOS

rev engine

Support for value and child events on Firebase iOS

Support for listening to value and child events

Roll to mojo_sdk 0.2.9.

JNI/Dart: support for more data types

* Conversion of all primitive types, wrapped Java objects, and nulls between Dart and Java
* A way to distinguish float arguments from doubles when calling Java methods
* Construction of a Dart JniClass from a Java class object

Fix typo in image raster offset

We shouldn't plumb the "right" value into the y coordinate.

Remove Xcode harness for building the engine

Stocks FAB "+" sometimes teleports to near the top left

The matrix argument to drawPicture doesn't seem to do what we want exactly.
Instead, use the normal matrix in the canvas. Also, handle cull rects with
non-zero left and top coordinates.

Fixes #1229

Move //sky/compositor to //flow

Now that the compositor doesn't have any tricky deps, we can make it a
top-level project, which saves a bunch of typing.