Raise an exception when converting a DartWrappable with empty native …

Support Android x86.

Mention the waterfall and conventions around it.

more dart:ui dartdocs

Also rolls Dart to include their Android x86 fixes.

@jason-simmons @chinmaygarde @abarth

Fix crash when running widget example

Dart_IsolateMakeRunnable was returning false, which can indicate that the
isolate was already running. This patch seems harmless, but I'll follow up to
understand more about what's happening here.

Fixes #2383

Fixes https://github.com/flutter/flutter/issues/2391

Dont include any of the machinery to generate a precompilation snapshot on the embedder VM

Ignore checked mode when running from a precompilation snapshot.

Remove packages/material_design_icons

We no longer use a pub package to distribute these icons.

Fix startup crash caused by mojo roll.

Add GCM to gitignore

Update Mojo

Remove obsolete AssetBundle implementations

Rename DOMDartState to UIDartState

Reland _embedder.yaml support to Flutter engine

Implement support for invoking Mojo services from secondary isolates

Add Rect.fromCircle

Add a license header to RRect.dart

Fixes https://github.com/flutter/flutter/issues/1502

As requested.

Add Color#withOpacity

Add new Size.fromRadius()

Fixes https://github.com/flutter/flutter/issues/2277